TRINAMIC TMC2209-BOB Datasheet

POWER DRIVER FOR STEPPER MOTORS INTEGRATED CIRCUITS

TRINAMIC Motion Control GmbH & Co. KG
Hamburg, Germany

TMC2209 Datasheet

APPLICATIONS

Compatible Design Upgrade
3D Printers
Printers, POS
Office and home automation
Textile, Sewing Machines
CCTV, Security
ATM, Cash recycler
HVAC
Battery Operated Equipment

FEATURES AND BENEFITS

2-phase stepper motors up to 2.8A coil current (peak), 2A RMS
STEP/DIR Interface with 8, 16, 32 or 64 microstep pin setting
Smooth Running 256 microsteps by MicroPlyer™ interpolation

StealthChop2™ silent motor operation

SpreadCycle™ highly dynamic motor control chopper
StallGuard4™ load and stall detection for StealthChop
CoolStep™ current control for energy savings up to 75%

Low RDSon, Low Heat-Up LS 170mΩ & HS 170mΩ (typ. at 25°C)
Voltage Range 4.75… 29V DC
Low Power Standby to fit standby energy regulations

Internal Sense Resistor option (no sense resistors required)
Passive Braking, Freewheeling, and automatic power down
Single Wire UART & OTP for advanced configuration options
Integrated Pulse Generator for standalone motion
Full Protection & Diagnostics
Compact QFN package with large heat slug

DESCRIPTION

The TMC2209 is an ultra-silent motor driver
IC for two phase stepper motors. TMC2209
pinning is similar to a number of legacy
drivers as well as to the TMC2208.
TRINAMICs sophisticated StealthChop2
chopper ensures noiseless operation,
maximum efficiency and best motor torque.
Its fast current regulation and optional
combination with SpreadCycle allow highly
dynamic motion while adding. StallGuard
for sensorless homing. The integrated
power MOSFETs handle motor currents up
to 2A RMS with protection and diagnostic
features for robust and reliable operation.
A simple to use UART interface opens up
tuning and control options. Store
application tuning to OTP memory.
Industries’ most advanced STEP/DIR
stepper motor driver family upgrades
designs to noiseless and most precise
operation for cost-effective and highly
competitive solutions.

Step/Dir Drivers for Two-Phase Bipolar Stepper Motors up to 2.8A peak – StealthChop™ for Quiet
Movement – UART Interface Option – Sensorless Stall Detection StallGuard4.

BLOCK DIAGRAM

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4

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 2

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APPLICATION EXAMPLES: SIMPLE SOLUTIONS – HIGHLY EFFECTIVE

The TMC22xx family scores with power density, integrated power MOSFETs, smooth and quiet
operation, and a congenial simplicity. The TMC2209 covers a wide spectrum of applications from
battery systems to embedded applications with up to 2A motor current per coil. TRINAMICs unique
chopper modes SpreadCycle and StealthChop2 optimize drive performance. StealthChop reduces motor
noise to the point of silence at low velocities. Standby current reduction keeps costs for power
dissipation and cooling down. Extensive support enables rapid design cycles and fast time-to-market
with competitive products.

STANDALONE REPLACEMENT FOR LEGACY STEPPER DRIVER

S/D

N

S

0A+

0A-

0B+

TMC22xx

0B-

ERROR, INDEX

S/D

N

S

0A+

0A-

0B+

TMC22xx

0B-

UART

CPU

High-Level

Interface

UART INTERFACE FOR FULL DIAGNOSTICS AND CONTROL

Sense Resistors may be omitted

ORDER CODES

Order code

PN

Description

Size [mm2]

TMC2209-LA

00-0173

StealthChop standalone driver; QFN28 (RoHS compliant)

5 x 5

TMC2209-LA-T

00-0173-T

-T denotes tape on reel packing of devices

TMC2209-EVAL

40-0169

Evaluation board for TMC2209 stepper motor driver

85 x 55

ESELSBRÜCKE

40-0098

Connector board fitting to Landungsbrücke

61 x 38

LANDUNGSBRÜCKE

40-0167

Baseboard for TMC2209-EVAL & further evaluation
boards

85 x 55

In this example, configuration is hard
wired via pins. Software based motion
control generates STEP and DIR
(direction) signals, INDEX and ERROR
signals report back status information.

A CPU operates the driver via step and
direction signals. It accesses diagnostic
information and configures the
TMC2209 via the UART interface. The
CPU manages motion control and the
TMC2209 drives the motor and smoo­thens and optimizes drive performance.

The TMC2209-EVAL is part of
TRINAMICs universal evaluation board
system which provides a convenient
handling of the hardware as well as a
user-friendly software tool for
evaluation. The TMC2209 evaluation
board system consists of three parts:
STARTRAMPE (base board),
ESELSBRÜCKE (connector board with
several test points and stand-alone
settings), and TMC2209-EVAL.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 3

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Table of Contents

1 PRINCIPLES OF OPERATION ......................... 4

1.1 KEY CONCEPTS ................................................ 5

1.2 CONTROL INTERFACES ..................................... 6

1.3 MOVING AND CONTROLLING THE MOTOR ........ 6

1.4 STEALTHCHOP2 & SPREADCYCLE DRIVER ....... 6

1.5 STALLGUARD4 – MECHANICAL LOAD SENSING .

....................................................................... 7

1.6 COOLSTEP – LOAD ADAPTIVE CURRENT

CONTROL ...................................................................... 7

1.7 AUTOMATIC STANDSTILL POWER DOWN......... 8

1.8 INDEX OUTPUT ................................................ 8

1.9 PRECISE CLOCK GENERATOR AND CLK INPUT... 8

2 PIN ASSIGNMENTS ........................................... 9

2.1 PACKAGE OUTLINE TMC2209 ........................ 9

2.2 SIGNAL DESCRIPTIONS TMC2209 .................. 9

3 SAMPLE CIRCUITS .......................................... 11

3.1 STANDARD APPLICATION CIRCUIT ................ 11

3.2 INTERNAL RDSON SENSING .......................... 11

3.3 5V ONLY SUPPLY .......................................... 12

3.4 CONFIGURATION PINS .................................. 13

3.5 HIGH MOTOR CURRENT ................................. 13

3.6 LOW POWER STANDBY ................................. 14

3.7 DRIVER PROTECTION AND EME CIRCUITRY ... 14

4 UART SINGLE WIRE INTERFACE ................ 15

4.1 DATAGRAM STRUCTURE ................................. 15

4.2 CRC CALCULATION ....................................... 17

4.3 UART SIGNALS ............................................ 17

4.4 ADDRESSING MULTIPLE SLAVES .................... 18

5 REGISTER MAP ................................................. 19

5.1 GENERAL REGISTERS ..................................... 20

5.2 VELOCITY DEPENDENT CONTROL ................... 25

5.3 STALLGUARD CONTROL ................................. 26

5.4 SEQUENCER REGISTERS ................................. 28

5.5 CHOPPER CONTROL REGISTERS ..................... 29

6 STEALTHCHOP™ .............................................. 35

6.1 AUTOMATIC TUNING ..................................... 35

6.2 STEALTHCHOP OPTIONS ................................ 37

6.3 STEALTHCHOP CURRENT REGULATOR ............. 37

6.4 VELOCITY BASED SCALING ............................ 39

6.5 COMBINE STEALTHCHOP AND SPREADCYCLE . 41

6.6 FLAGS IN STEALTHCHOP ............................... 42

6.7 FREEWHEELING AND PASSIVE BRAKING ........ 43

7 SPREADCYCLE CHOPPER ............................... 45

7.1 SPREADCYCLE SETTINGS ............................... 46

8 SELECTING SENSE RESISTORS .................... 49

9 MOTOR CURRENT CONTROL ........................ 50

9.1 ANALOG CURRENT SCALING VREF ............... 51

10 INTERNAL SENSE RESISTORS ..................... 53

11 STALLGUARD4 LOAD MEASUREMENT ....... 55

11.1 STALLGUARD4 VS. STALLGUARD2 ................ 55

11.2 TUNING STALLGUARD4 ................................. 56

11.3 STALLGUARD4 UPDATE RATE ....................... 56

11.4 DETECTING A MOTOR STALL ......................... 56

11.5 LIMITS OF STALLGUARD4 OPERATION .......... 56

12 COOLSTEP OPERATION ................................. 57

12.1 USER BENEFITS ............................................. 57

12.2 SETTING UP FOR COOLSTEP .......................... 57

12.3 TUNING COOLSTEP ....................................... 59

13 STEP/DIR INTERFACE .................................... 60

13.1 TIMING ......................................................... 60

13.2 CHANGING RESOLUTION ............................... 61

13.3 MICROPLYER STEP INTERPOLATOR AND STAND

STILL DETECTION ....................................................... 62

13.4 INDEX OUTPUT ............................................. 63

14 INTERNAL STEP PULSE GENERATOR ......... 64

15 DRIVER DIAGNOSTIC FLAGS ...................... 65

15.1 TEMPERATURE MEASUREMENT ....................... 65

15.2 SHORT PROTECTION ...................................... 65

15.3 OPEN LOAD DIAGNOSTICS ........................... 66

15.4 DIAGNOSTIC OUTPUT ................................... 66

16 QUICK CONFIGURATION GUIDE ................ 67

17 EXTERNAL RESET ............................................. 71

18 CLOCK OSCILLATOR AND INPUT ............... 71

19 ABSOLUTE MAXIMUM RATINGS ................. 72

20 ELECTRICAL CHARACTERISTICS ................. 72

20.1 OPERATIONAL RANGE ................................... 72

20.2 DC AND TIMING CHARACTERISTICS .............. 73

20.3 THERMAL CHARACTERISTICS.......................... 77

21 LAYOUT CONSIDERATIONS ......................... 78

21.1 EXPOSED DIE PAD ........................................ 78

21.2 WIRING GND .............................................. 78

21.3 SUPPLY FILTERING ........................................ 78

21.4 LAYOUT EXAMPLE TMC2209 ........................ 79

22 PACKAGE MECHANICAL DATA .................... 80

22.1 DIMENSIONAL DRAWINGS QFN28 ............... 80

22.2 PACKAGE CODES ........................................... 81

23 TABLE OF FIGURES ......................................... 82

24 REVISION HISTORY ....................................... 83

25 REFERENCES ...................................................... 83

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 4

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1 Principles of Operation

The TMC22xx family of stepper drivers is intended as a drop-in upgrade for existing low-cost stepper
driver applications. Their silent drive technology StealthChop enables non-bugging motion control for
home and office applications. A highly efficient power stage enables high current from a tiny package.

The TMC2209 requires just a few control pins on its tiny package. It allows selection of the most
important setting: the desired microstep resolution. A choice of 8, 16, 32 or 64 microsteps, or from
fullstep up to 1/256 step adapts the driver to the capabilities of the motion controller.

Even at low microstepping rate, the TMC2209 offers a number of unique enhancements over
comparable products: TRINAMICs sophisticated StealthChop2 chopper plus the microstep enhancement
MicroPlyer ensure noiseless operation, maximum efficiency and best motor torque. Its fast current
regulation and optional combination with SpreadCycle allow for highly dynamic motion. Protection
and diagnostic features support robust and reliable operation. A simple-to-use 8 bit UART interface
opens up more tuning and control options. Application specific tuning can be stored to on-chip OTP
memory. Industries’ most advanced step & direction stepper motor driver family upgrades designs to
noiseless and most precise operation for cost-effective and highly competitive solutions.

22n

50V

100n

16V

ENN

GND

DIE PAD

microPlyer

Full Bridge A

Full Bridge B

+V

M

VS

stepper
motor

N

S

OA1

OA2

OB1

OB2

Driver

100n

BRB

100µF

CPI

CPO

BRA

R

SA

Use low inductivity SMD

type, e.g. 1206, 0.5W for

RSA and R

SB

R

SB

100n

VCP

VREF

opt. driver enable

stealthChop2

spreadCycle

Integrated

Rsense

IREF

256 Microstep

Sequencer

Stand Still

Current

Reduction

2.2µ

6.3V

5VOUT

Analog current

scaling or leave

open

Low ESR type

Place near IC with

short path to die pad

Connect directly

to GND plane

Connect directly

to GND plane

VCC_IO

TMC2209

Step&Dir input

5V Voltage

regulator

charge pump

CLK_IN

opt. ext. clock

10-16MHz

3.3V or 5V

I/O voltage

100n

Analog Scaling

VREF

Programmable

Diagnostic

Outputs

Configuration

Interface

MS1

MS2

SPREAD

INDEX

DIAG

Configuration

(GND or VCC_IO)

Index pulse

Driver error

PDN/UART

B. Dwersteg, ©

TRINAMIC 2016

Trimmed

CLK oscillator/

selector

UART interface

+ Register Block

Configuration

Memory (OTP)

optional UART interface

IREF

Step Pulse

Generator

STEP

DIR

Step and Direction

motion control

stallGuard4

coolStep

STDBY

opt. low power standby

Figure 1.1 TMC2209 basic application block diagram

THREE MODES OF OPERATION:

OPTION 1: Standalone STEP/DIR Driver (Legacy Mode)

A CPU (µC) generates step & direction signals synchronized to additional motors and other
components within the system. The TMC2209 operates the motor as commanded by the configuration
pins and STEP/DIR signals. Motor run-current either is fixed, or set by the CPU using the analog input
VREF. The pin PDN_UART selects automatic standstill current reduction. Feedback from the driver to

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 5

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the CPU is granted by the INDEX and DIAG output signals. Enable or disable the motor using the ENN
pin.

OPTION 2: Standalone STEP/DIR Driver with OTP pre-configuration

Additional options enabled by pre-programming OTP memory (label UART & OTP):

+ Tuning of the chopper to the application for application tailored performance
+ Cost reduction by switching the driver to internal sense resistor mode
+ Adapting the automatic power down level and timing for best application efficiency

S/D

N

S

0A+

0A-

0B+

TMC22xx

0B-

ERROR, INDEX

CPU

High-Level

Interface

TXD only or bit

bang UART

Other drivers

External pre-

programming

Figure 1.2 Stand-alone driver with pre-configuration

To enable the additional options, either one-time program the driver’s OTP memory, or store
configuration in the CPU and transfer it to the on-chip registers following each power-up. Operation
uses the same signals as Option 1. Programming does not need to be done within the application - it
can be executed during testing of the PCB! Alternatively, use bit-banging by CPU firmware to configure
the driver. Multiple drivers can be programmed at the same time using a single TXD line.

OPTION 3: STEP/DIR Driver with Full Diagnostics and Control

Similar to Option 2, but pin PDN_UART is connected to the CPU UART interface.
Additional options (label UART):

+ Detailed diagnostics and thermal management
+ Passive braking and freewheeling for flexible, lowest power stop modes
+ More options for microstep resolution setting (fullstep to 256 microstep)
+ Software controlled motor current setting and more chopper options
+ Use StallGuard for sensorless homing and CoolStep for adaptive motor current and cool motor

This mode allows replacing all control lines like ENN, DIAG, INDEX, MS1, MS2, and analog current
setting VREF by a single interface line. This way, only three signals are required for full control: STEP,
DIR and PDN_UART. Even motion without external STEP pulses is provided by an internal
programmable step pulse generator: Just set the desired motor velocity. However, no ramping is
provided by the TMC2209.

1.1 Key Concepts

The TMC2209 implements advanced features which are exclusive to TRINAMIC products. These features
contribute toward greater precision, greater energy efficiency, higher reliability, smoother motion, and
cooler operation in many stepper motor applications.

StealthChop2™ No-noise, high-precision chopper algorithm for inaudible motion and inaudible

standstill of the motor. Allows faster motor acceleration and deceleration than
StealthChop™ and extends StealthChop to low stand still motor currents.

SpreadCycle™ High-precision cycle-by-cycle current control for highest dynamic movements.
MicroPlyer™ Microstep interpolator for obtaining full 256 microstep smoothness with lower

resolution step inputs starting from fullstep

StallGuard4™ Sensorless homing safes end switches and warns in case of motor overload
CoolStep™ Uses StallGuard measurement in order to adapt the motor current for best efficiency

and lowest heat-up of motor and driver

UART

UART OTP

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 6

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In addition to these performance enhancements, TRINAMIC motor drivers offer safeguards to detect
and protect against shorted outputs, output open-circuit, overtemperature, and undervoltage
conditions for enhancing safety and recovery from equipment malfunctions.

1.2 Control Interfaces

The TMC2209 supports both, discrete control lines for basic mode selection and a UART based single
wire interface with CRC checking. The UART interface automatically becomes enabled when correct
UART data is sent. When using UART, the pin selection may be disabled by control bits.

1.2.1 UART Interface

The single wire interface allows unidirectional operation (for parameter setting only), or bi-directional
operation for full control and diagnostics. It can be driven by any standard microcontroller UART or
even by bit banging in software. Baud rates from 9600 Baud to 500k Baud or even higher (when
using an external clock) may be used. No baud rate configuration is required, as the TMC2209
automatically adapts to the masters’ baud rate. The frame format is identical to the intelligent
TRINAMIC controller & driver ICs TMC5130, TMC516x and TMC5072. A CRC checksum allows data
transmission over longer distance. For fixed initialization sequences, store the data including CRC into
the µC, thus consuming only a few 100 bytes of code for a full initialization. CRC may be ignored
during read access, if not desired. This makes CRC use an optional feature! The IC supports four
address settings to access up to four ICs on a single bus. Even more drivers can be programmed in
parallel by tying together all interface pins, in case no read access is required. An optional addressing
can be provided by analog multiplexers, like 74HC4066.

From a software point of view the TMC2209 is a peripheral with a number of control and status
registers. Most of them can either be written only or are read only. Some of the registers allow both,
read and write access. In case read-modify-write access is desired for a write only register, realize a
shadow register in master software.

1.3 Moving and Controlling the Motor

1.3.1 STEP/DIR Interface

The motor is controlled by a step and direction input. Active edges on the STEP input can be rising
edges or both rising and falling edges as controlled by a special mode bit (DEDGE). Using both edges
cuts the toggle rate of the STEP signal in half, which is useful for communication over slow interfaces
such as optically isolated interfaces. The state sampled from the DIR input upon an active STEP edge
determines whether to step forward or back. Each step can be a fullstep or a microstep, in which
there are 2, 4, 8, 16, 32, 64, 128, or 256 microsteps per fullstep. A step impulse with a low state on
DIR increases the microstep counter and a high decreases the counter by an amount controlled by the
microstep resolution. An internal table translates the counter value into the sine and cosine values
which control the motor current for microstepping.

1.3.2 Internal Step Pulse Generator

Some applications do not require a precisely co-ordinate motion – the motor just is required to move
for a certain time and at a certain velocity. The TMC2209 comes with an internal pulse generator for
these applications: Just provide the velocity via UART interface to move the motor. The velocity sign
automatically controls the direction of the motion. However, the pulse generator does not integrate a
ramping function. Motion at higher velocities will require ramping up and ramping down the velocity
value via software.

STEP/DIR mode and internal pulse generator mode can be mixed in an application!

1.4 StealthChop2 & SpreadCycle Driver

StealthChop is a voltage-chopper based principle. It especially guarantees that the motor is absolutely
quiet in standstill and in slow motion, except for noise generated by ball bearings. Unlike other
voltage mode choppers, StealthChop2 does not require any configuration. It automatically learns the

UART

UART

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 7

www.trinamic.com

best settings during the first motion after power up and further optimizes the settings in subsequent
motions. An initial homing sequence is sufficient for learning. Optionally, initial learning parameters
can be stored to OTP. StealthChop2 allows high motor dynamics, by reacting at once to a change of
motor velocity.

For highest velocity applications, SpreadCycle is an option to StealthChop2. It can be enabled via
input pin or via UART and OTP. StealthChop2 and SpreadCycle may even be used in a combined
configuration for the best of both worlds: StealthChop2 for no-noise stand still, silent and smooth
performance, SpreadCycle at higher velocity for high dynamics and highest peak velocity at low
vibration.

SpreadCycle is an advanced cycle-by-cycle chopper mode. It offers smooth operation and good
resonance dampening over a wide range of speed and load. The SpreadCycle chopper scheme
automatically integrates and tunes fast decay cycles to guarantee smooth zero crossing performance.

Benefits of using StealthChop2:

- Significantly improved microstepping with low cost motors

- Motor runs smooth and quiet

- Absolutely no standby noise

- Reduced mechanical resonance yields improved torque

1.5 StallGuard4 – Mechanical Load Sensing

StallGuard4 provides an accurate measurement of the load on the motor. It can be used for stall
detection as well as other uses at loads below those which stall the motor, such as CoolStep load­adaptive current reduction. This gives more information on the drive allowing functions like
sensorless homing and diagnostics of the drive mechanics.

1.6 CoolStep – Load Adaptive Current Control

coolStep drives the motor at the optimum current. It uses the stallGuard4 load measurement
information to adjust the motor current to the minimum amount required in the actual load situation.
This saves energy and keeps the components cool.

Benefits are:

- Energy efficiency power consumption decreased up to 75%

- Motor generates less heat improved mechanical precision

- Less or no cooling improved reliability

- Use of smaller motor less torque reserve required → cheaper motor does the job

- Less motor noise Due to less energy exciting motor resonances

Figure 1.3 shows the efficiency gain of a 42mm stepper motor when using coolStep compared to
standard operation with 50% of torque reserve. coolStep is enabled above 60RPM in the example.

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

0 50 100 150 200 250 300 350

Efficiency

Velocity [RPM]

Efficiency with coolStep

Efficiency with 50% torque reserve

Figure 1.3 Energy efficiency with coolStep (example)

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 8

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1.7 Automatic Standstill Power Down

An automatic current reduction drastically reduces application power dissipation and cooling
requirements. Per default, the stand still current reduction is enabled by pulling PDN_UART input to
GND. It reduces standstill power dissipation to less than 33% by going to slightly more than half of
the run current.
Modify stand still current, delay time and decay via UART, or pre-programmed via internal OTP.
Automatic freewheeling and passive motor braking are provided as an option for stand still. Passive
braking reduces motor standstill power consumption to zero, while still providing effective
dampening and braking!

t

CURRENT

TPOWERDOWN

power down

delay time

RMS motor current trace with pin PDN=0

IHOLD

IRUN

IHOLDDELAY

power down

ramp time

STEP

Figure 1.4 Automatic Motor Current Power Down

1.8 Index Output

The index output gives one pulse per electrical rotation, i.e. one pulse per each four fullsteps. It
shows the internal sequencer microstep 0 position (MSTEP near 0). This is the power on position. In
combination with a mechanical home switch, a more precise homing is enabled.

1.9 Precise clock generator and CLK input

The TMC2209 provides a factory trimmed internal clock generator for precise chopper frequency and
performance. However, an optional external clock input is available for cases, where quartz precision
is desired, or where a lower or higher frequency is required. For safety, the clock input features
timeout detection, and switches back to internal clock upon fail of the external source.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 9

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2 Pin Assignments

The TMC2209 comes in a compact QFN package.

2.1 Package Outline TMC2209

OB2
ENN

GND

CPO

SPREAD

OB1

BRA

CLK

INDEX

MS2_AD1

DIAG

STEP

VREF

GND

DIR

STDBY

OA2

CPI

VCP

PDN_UART

MS1_AD0

5VOUT

OA1

-

BRB

VS

VS

VCC_IO

1 2 3 4 5 6 7

21201918171615

22232425262728

141312111098

TMC2209

QFN28

Pad=GND

© B. Dwersteg,

TRINAMIC

Figure 2.1 TMC2209 Pinning Top View – type: QFN28, 5x5mm², 0.5mm pitch

2.2 Signal Descriptions TMC2209

Pin

Number

Type

Function

OB2

1 Motor coil B output 2

ENN

2

DI

Enable not input. The power stage becomes switched off (all motor
outputs floating) when this pin becomes driven to a high level.

GND

3, 18

GND. Connect to GND plane near pin.

CPO

4 Charge pump capacitor output.

CPI 5

Charge pump capacitor input. Tie to CPO using 22nF 50V capacitor.

VCP 6

Charge pump voltage. Tie to VS using 100nF capacitor.

SPREAD

7

DI (pd)

Chopper mode selection: Low=StealthChop, High=SpreadCycle
(may be left unconnected)

5VOUT

8

Output of internal 5V regulator. Attach 2.2µF to 4.7µF ceramic
capacitor to GND near to pin for best performance. Provide the
shortest possible loop to the GND pad.

MS1_AD0

9

DI (pd)

Microstep resolution configuration (internal pull-down resistors)
MS2, MS1: 00: 1/8, 01: 1/32, 10: 1/64 11: 1/16
For UART based configuration selection of UART Address 0…3

MS2_AD1

10

DI (pd)

DIAG

11

DO

Diagnostic and StallGuard output. Hi level upon stall detection or
driver error. Reset error condition by ENN=high.

INDEX

12

DO

Configurable index output. Provides index pulse.

CLK

13

DI

CLK input. Tie to GND using short wire for internal clock or supply
external clock.

PDN_UART

14

DIO

Power down not control input (low = automatic standstill current
reduction).
Optional UART Input/Output. Power down function can be disabled
in UART mode.

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Pin

Number

Type

Function

VCC_IO

15 3.3V to 5V IO supply voltage for all digital pins.

STEP

16

DI

STEP input

VREF

17

AI

Analog reference voltage for current scaling or reference current for
use of internal sense resistors (optional mode)

DIR

19

DI (pd)

DIR input (internal pull-down resistor)

STDBY

20

DI (pd)

STANDBY input. Pull up to disable driver internal supply regulator.
This will bring the driver into a low power dissipation state.
100kOhm pulldown. (may be left unconnected)

Hint: Also shut down VREF voltage and ENN to 0V during standby.

VS

22, 28

Motor supply voltage. Provide filtering capacity near pin with
shortest possible loop to GND pad.

OA2

21 Motor coil A output 2

BRA

23

Sense resistor connection for coil A. Place sense resistor to GND near
pin. Tie to GND when using internal sense resistor.

OA1

24 Motor coil A output 1

-

25

unused

May be connected to GND for better PCB routing

OB1

26 Motor coil B output 1

BRB

27

Sense resistor connection for coil B. Place sense resistor to GND near
pin. Tie to GND when using internal sense resistor.

Exposed
die pad

-

Connect the exposed die pad to a GND plane. Provide as many as
possible vias for heat transfer to GND plane. Serves as GND pin for
power drivers and analogue circuitry.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 11

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3 Sample Circuits

The sample circuits show the connection of external components in different operation and supply
modes. The connection of the bus interface and further digital signals is left out for clarity.

3.1 Standard Application Circuit

22n

50V

100n

16V

ENN

GND

DIE PAD

microPlyer

Full Bridge A

Full Bridge B

+V

M

VS

stepper
motor

N

S

OA1

OA2

OB1

OB2

Driver

100n

BRB

100µF

CPI

CPO

BRA

R

SA

Use low inductivity SMD

type, e.g. 1206, 0.5W for

RSA and R

SB

R

SB

100n

VCP

VREF

opt. driver enable

stealthChop2

spreadCycle

Integrated

Rsense

IREF

256 Microstep

Sequencer

Stand Still

Current

Reduction

2.2µ

6.3V

5VOUT

Analog current

scaling or leave

open

Low ESR type

Place near IC with

short path to die pad

Connect directly

to GND plane

Connect directly

to GND plane

VCC_IO

TMC2209

Step&Dir input

5V Voltage

regulator

charge pump

CLK_IN

opt. ext. clock

10-16MHz

3.3V or 5V

I/O voltage

100n

Analog Scaling

VREF

Programmable

Diagnostic

Outputs

Configuration

Interface

MS1

MS2

SPREAD

INDEX

DIAG

Configuration

(GND or VCC_IO)

Index pulse

Driver error

PDN/UART

B. Dwersteg, ©

TRINAMIC 2016

Trimmed

CLK oscillator/

selector

UART interface

+ Register Block

Configuration

Memory (OTP)

optional UART interface

IREF

Step Pulse

Generator

STEP

DIR

Step and Direction

motion control

stallGuard4

coolStep

STDBY

opt. low power standby

Figure 3.1 Standard application circuit

The standard application circuit uses a minimum set of additional components. Two sense resistors
set the motor coil current. See chapter 8 to choose the right sense resistors. Use low ESR capacitors
for filtering the power supply. The capacitors need to cope with the current ripple cause by chopper
operation. A minimum capacity of 100µF near the driver is recommended for best performance.
Current ripple in the supply capacitors also depends on the power supply internal resistance and
cable length. VCC_IO can be supplied from 5VOUT, or from an external source, e.g. a 3.3V regulator.

Basic layout hints

Place sense resistors and all filter capacitors as close as possible to the related IC pins. Use a solid
common GND for all GND connections, also for sense resistor GND. Connect 5VOUT filtering capacitor
directly to 5VOUT and the die pad. See layout hints for more details. Low ESR electrolytic capacitors
are recommended for VS filtering.

3.2 Internal RDSon Sensing

For cost critical or space limited applications, sense resistors can be omitted. For internal current
sensing, a reference current set by a tiny external resistor programs the output current. For calculation
of the reference resistor, refer chapter 9.1.

Attention

Be sure to switch the IC to RDSon mode, before enabling drivers: Set otp_internalRsense = 1.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 12

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VCC_IO

TMC2209

Step&Dir input

5V Voltage

regulator

charge pump

22n

50V

100n

16V

CLK_IN

ENN

GND

DIE PAD

opt. ext. clock

10-16MHz

3.3V or 5V

I/O voltage

100n

microPlyer

Full Bridge A

Full Bridge B

+V

M

VS

stepper
motor

N

S

OA1

OA2

OB1

OB2

Driver

100n

BRB

100µF

CPI

CPO

BRA

100n

VCP

Analog Scaling

VREF

VREF

opt. driver enable

Programmable

Diagnostic

Outputs

Configuration

Interface

MS1

MS2

SPREAD

INDEX

DIAG

Configuration

(GND/open or VCC_IO)

Index pulse

Driver error

PDN/UART

B. Dwersteg, ©

TRINAMIC 2016

Trimmed

CLK oscillator/

selector

UART interface

+ Register Block

Configuration

Memory (OTP)

stealthChop2

spreadCycle

Integrated

Rsense

IREF

IREF

256 Microstep

Sequencer

Step Pulse

Generator

Stand Still

Current

Reduction

STEP

DIR

2.2µ

6.3V

5VOUT

Step and Direction

motion control

R

REF

Attention:
Start with ENN=h igh!
Set GCONF.1 or OTP0.6
prior to enabling the driver!

Low ESR type

Connect directly

to GND plane

Connect directly

to GND plane

Place near IC with

short path to die pad

optional UART interface

stallGuard4

coolStep

STDBY

opt. low power standby

Figure 3.2 Application circuit using RDSon based sensing

3.3 5V Only Supply

22n

50V

100n

16V

ENN

GND

DIE PAD

microPlyer

Full Bridge A

Full Bridge B

4.7-5.4V

VS

stepper
motor

N

S

OA1

OA2

OB1

OB2

Driver

100n

BRB

100µF

CPI

CPO

BRA

R

SA

R

SB

100n

VCP

VREF

opt. driver enable

stealthChop2

spreadCycle

Integrated

Rsense

IREF

256 Microstep

Sequencer

Stand Still

Current

Reduction

10µ

6.3V

5VOUT

10R

Use low inductivity SMD
type, e.g. 1206, 0.5W for

RSA and R

SB

Low ESR type

Place near IC with

short path to die pad

Connect directly

to GND plane

Connect directly

to GND plane

VCC_IO

TMC2209

Step&Dir input

5V Voltage

regulator

charge pump

CLK_IN

opt. ext. clock

10-16MHz

3.3V or 5V

I/O voltage

100n

Analog Scaling

VREF

Programmable

Diagnostic

Outputs

Configuration

Interface

MS1

MS2

SPREAD

INDEX

DIAG

Configuration

(GND/open or VCC_IO)

Index pulse

Driver error

PDN/UART

B. Dwersteg, ©

TRINAMIC 2016

Trimmed

CLK oscillator/

selector

UART interface

+ Register Block

Configuration

Memory (OTP)

IREF

Step Pulse

Generator

STEP

DIR

Step and Direction

motion control

Optional – bridges the internal 5V
reference – leave away if standby is

desired

optional UART interface

stallGuard4

coolStep

STDBY

opt. low power standby

Figure 3.3 5V only operation

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 13

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While the standard application circuit is limited to roughly 5.2 V lower supply voltage, a 5 V only
application lets the IC run from a 5 V +/-5% supply. In this application, linear regulator drop must be
minimized. Therefore, the internal 5V regulator is filtered with a higher capacitance. An optional
resistor bridges the internal 5V regulator by connecting 5VOUT to the external power supply. This RC
filter keeps chopper ripple away from 5VOUT. With this resistor, the external supply is the reference
for the absolute motor current and must not exceed 5.5V. Standby function will not work in this
application, because the 5V regulator is bridged.

3.4 Configuration Pins

The TMC2209 provides four configuration pins. These pins allow quick configuration for standalone
operation. Several additional options can be set by OTP programming. In UART mode, the
configuration pins can be disabled in order to set a different configuration via registers.

PDN_UART: CONFIGURATION OF STANDSTILL POWER DOWN

PDN_UART

Current Setting

GND

Enable automatic power down in standstill periods

VCC_IO

Disable

UART interface

When using the UART interface, the configuration pin should be disabled via
GCONF.pdn_disable = 1. Program IHOLD as desired for standstill periods.

MS1/MS2: CONFIGURATION OF MICROSTEP RESOLUTION FOR STEP INPUT

MS2

MS1

Microstep Setting

GND

GND

8 microsteps

GND

VCC_IO

32 microsteps (different to TMC2208!)

VCC_IO

GND

64 microsteps (different to TMC2208!)

VCC_IO

VCC_IO

16 microsteps

SPREAD: SELECTION OF CHOPPER MODE

SPREAD

Chopper Setting

GND or
Pin open / not
available

StealthChop is selected. Automatic switching to SpreadCycle in dependence of
the step frequency can be programmed via OTP.
VCC_IO

SpreadCycle operation.

3.5 High Motor Current

When operating at a high motor current, the driver power dissipation due to MOSFET switch on­resistance significantly heats up the driver. This power dissipation will significantly heat up the PCB
cooling infrastructure, if operated at an increased duty cycle. This in turn leads to a further increase of
driver temperature. An increase of temperature by about 100°C increases MOSFET resistance by
roughly 50%. This is a typical behavior of MOSFET switches. Therefore, under high duty cycle, high
load conditions, thermal characteristics have to be carefully taken into account, especially when
increased environment temperatures are to be supported. Refer the thermal characteristics and the
layout hints for more information. As a thumb rule, thermal properties of the PCB design become
critical for the tiny QFN 5mm x 5mm package at or above 1.4A RMS motor current for increased
periods of time. Keep in mind that resistive power dissipation rises with the square of the motor
current. On the other hand, this means that a small reduction of motor current significantly saves heat
dissipation and energy.

Pay special attention to good thermal properties of your PCB layout, when going for 1.4A RMS current
or more.

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An effect which might be perceived at medium motor velocities and motor sine wave peak currents
above roughly 2A peak is a slight sine distortion of the current wave when using SpreadCycle. It
results from an increasing negative impact of parasitic internal diode conduction, which in turn
negatively influences the duration of the fast decay cycle of the SpreadCycle chopper. This is, because
the current measurement does not see the full coil current during this phase of the sine wave,
because an increasing part of the current flows directly from the power MOSFETs’ drain to GND and
does not flow through the sense resistor. This effect with most motors does not negatively influence
the smoothness of operation, as it does not impact the critical current zero transition. The effect does
not occur with StealthChop.

3.6 Low Power Standby

Battery powered applications, and mains powered applications conforming to standby energy saving
rules, often require a standby operation, where the power-supply remains on, but current draw goes
down to a low value. The TMC2209 supports standby operation of roughly 2mW (at 12V supply), or
<1mW at 5V supply using a dedicated pin STANDYBY. Pull up STANDBY to VCC_IO to go to low power
standby. VCC_IO may be dropped down to 1.5V during standby. A high level on STANDBY will disable
the internal 5V regulator and at the same time switches off all internal units. Prior to going to
STANDBY, stop the motor, and allow it to enter standstill current, or switch off the motor completely.
When in STANDBY, inputs ENN and VREF have to be driven to a low level. VCC_IO shall remain active
in standby mode. All driver registers are reset to their power-up defaults after leaving standby mode.

3.7 Driver Protection and EME Circuitry

Some applications have to cope with ESD events caused by motor operation or external influence.
Despite ESD circuitry within the driver chips, ESD events occurring during operation can cause a reset
or even a destruction of the motor driver, depending on their energy. Especially plastic housings and
belt drive systems tend to cause ESD events of several kV. It is best practice to avoid ESD events by
attaching all conductive parts, especially the motors themselves to PCB ground, or to apply electrically
conductive plastic parts. In addition, the driver can be protected up to a certain degree against ESD
events or live plugging / pulling the motor, which also causes high voltages and high currents into
the motor connector terminals. A simple scheme uses capacitors at the driver outputs to reduce the
dV/dt caused by ESD events. Larger capacitors will bring more benefit concerning ESD suppression,
but cause additional current flow in each chopper cycle, and thus increase driver power dissipation,
especially at high supply voltages. The values shown are example values – they may be varied
between 100pF and 1nF. The capacitors also dampen high frequency noise injected from digital parts
of the application PCB circuitry and thus reduce electromagnetic emission. A more elaborate scheme
uses LC filters to de-couple the driver outputs from the motor connector. Varistors in between of the
coil terminals eliminate coil overvoltage caused by live plugging. Optionally protect all outputs by a
varistor to GND against ESD voltage.

Full Bridge A

Full Bridge B

stepper
motor

N

S

OA1

OA2

OB1

OB2

Driver

470pF
100V

470pF
100V

470pF
100V

470pF
100V

Full Bridge A

Full Bridge B

stepper
motor

N

S

OA1

OA2

OB1

OB2

Driver

470pF
100V

470pF
100V

50Ohm @

100MHz

50Ohm @

100MHz

50Ohm @

100MHz

50Ohm @

100MHz

V1

V2

Fit varistors to supply voltage

rating. SMD inductivities

conduct full motor coil

current.

470pF
100V

470pF
100V

Varistors V1 and V2 protect
against inductive motor coil
overvoltage.

V1A, V1B, V2A, V2B:
Optional position for varistors
in case of heavy ESD events.

BRB

R

SA

BRA

100nF
16V

R

SB

100nF
16V

V1A

V1B

V2A

V2B

Figure 3.4 Simple ESD enhancement and more elaborate motor output protection

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 15

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4 UART Single Wire Interface

The UART single wire interface allows control of the TMC2209 with any microcontroller UART. It shares
transmit and receive line like an RS485 based interface. Data transmission is secured using a cyclic
redundancy check, so that increased interface distances (e.g. over cables between two PCBs) can be
bridged without danger of wrong or missed commands even in the event of electro-magnetic
disturbance. The automatic baud rate detection makes this interface easy to use.

4.1 Datagram Structure

4.1.1 Write Access

UART WRITE ACCESS DATAGRAM STRUCTURE

each byte is LSB…MSB, highest byte transmitted first

0 … 63

sync + reserved

8 bit slave

address

RW + 7 bit

register addr.

32 bit data

CRC

0…7

8…15

16…23

24…55

56…63

1 0 1

0

Reserved (don’t cares

but included in CRC)

SLAVEADDR=0…3

register
address

1

data bytes 3, 2, 1, 0

(high to low byte)

CRC

0 1 2 3 4 5 6 7 8

…

15

16 … 23

24 … 55

56 … 63

A sync nibble precedes each transmission to and from the TMC2209 and is embedded into the first
transmitted byte, followed by an addressing byte (0 to 3 for TMC2209, depending on address setting).
Each transmission allows a synchronization of the internal baud rate divider to the master clock. The
actual baud rate is adapted and variations of the internal clock frequency are compensated. Thus, the
baud rate can be freely chosen within the valid range. Each transmitted byte starts with a start bit
(logic 0, low level on pin UART) and ends with a stop bit (logic 1, high level on UART). The bit time is
calculated by measuring the time from the beginning of start bit (1 to 0 transition) to the end of the
sync frame (1 to 0 transition from bit 2 to bit 3). All data is transmitted bytewise. The 32 bit data
words are transmitted with the highest byte first.

A minimum baud rate of 9000 baud is permissible, assuming 20 MHz clock (worst case for low baud
rate). Maximum baud rate is f

CLK

/16 due to the required stability of the baud clock.

The slave address SLAVEADDR is selected by MS1 (bit 0) and MS2 (bit 1) in the range 0 to 3.
Bit 7 of the register address identifies a Read (0) or a Write (1) access. Example: Address 0x10 is
changed to 0x90 for a write access.

The communication becomes reset if a pause time of longer than 63 bit times between the start bits
of two successive bytes occurs. This timing is based on the last correctly received datagram. In this
case, the transmission needs to be restarted after a failure recovery time of minimum 12 bit times of
bus idle time. This scheme allows the master to reset communication in case of transmission errors.
Any pulse on an idle data line below 16 clock cycles will be treated as a glitch and leads to a timeout
of 12 bit times, for which the data line must be idle. Other errors like wrong CRC are also treated the
same way. This allows a safe re-synchronization of the transmission after any error conditions.
Remark, that due to this mechanism an abrupt reduction of the baud rate to less than 15 percent of
the previous value is not possible.

Each accepted write datagram becomes acknowledged by the receiver by incrementing an internal
cyclic datagram counter (8 bit). Reading out the datagram counter allows the master to check the
success of an initialization sequence or single write accesses. Read accesses do not modify the
counter.

UART

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The UART line must be logic high during idle state. Therefore, the power down function cannot be
assigned by the pin PDN_UART in between of transmissions. In an application using the UART
interface, set the desired power down function by register access and set pdn_disable in GCONF to
disable the pin function.

4.1.2 Read Access

UART READ ACCESS REQUEST DATAGRAM STRUCTURE

each byte is LSB…MSB, highest byte transmitted first

sync + reserved

8 bit slave address

RW + 7 bit register

address

CRC

0...7

8…15

16…23

24…31

1 0 1

0

Reserved (don’t cares

but included in CRC)

SLAVEADDR=0…3

register address

0

CRC

0 1 2 3 4 5 6 7 8

…

15

16 … 23

24 … 31

The read access request datagram structure is identical to the write access datagram structure, but
uses a lower number of user bits. Its function is the addressing of the slave and the transmission of
the desired register address for the read access. The TMC2209 responds with the same baud rate as
the master uses for the read request.

In order to ensure a clean bus transition from the master to the slave, the TMC2209 does not
immediately send the reply to a read access, but it uses a programmable delay time after which the
first reply byte becomes sent following a read request. This delay time can be set in multiples of
eight bit times using SENDDELAY time setting (default=8 bit times) according to the needs of the
master.

UART READ ACCESS REPLY DATAGRAM STRUCTURE

each byte is LSB…MSB, highest byte transmitted first

0 ...... 63

sync + reserved

8 bit master

address

RW + 7 bit

register addr.

32 bit data

CRC

0…7

8…15

16…23

24…55

56…63

1 0 1 0 reserved (0)

0xFF

register
address

0

data bytes 3, 2, 1, 0

(high to low byte)

CRC

0 1 2 3 4 5 6 7 8

…

15

16 … 23

24 … 55

56 … 63

The read response is sent to the master using address code %11111111. The transmitter becomes
switched inactive four bit times after the last bit is sent.

Address %11111111 is reserved for read access replies going to the master.

Hint

Find an example for generating read and write datagrams in the TMC2209 calculation sheet.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 17

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4.2 CRC Calculation

An 8 bit CRC polynomial is used for checking both read and write access. It allows detection of up to
eight single bit errors. The CRC8-ATM polynomial with an initial value of zero is applied LSB to MSB,
including the sync- and addressing byte. The sync nibble is assumed to always be correct. The
TMC2209 responds only to correctly transmitted datagrams containing its own slave address. It
increases its datagram counter for each correctly received write access datagram.

    



SERIAL CALCULATION EXAMPLE

CRC = (CRC << 1) OR (CRC.7 XOR CRC.1 XOR CRC.0 XOR [new incoming bit])

C-CODE EXAMPLE FOR CRC CALCULATION

void swuart_calcCRC(UCHAR* datagram, UCHAR datagramLength)

{

int i,j;

UCHAR* crc = datagram + (datagramLength-1); // CRC located in last byte of message
UCHAR currentByte;

*crc = 0;

for (i=0; i<(datagramLength-1); i++) { // Execute for all bytes of a message

currentByte = datagram[i]; // Retrieve a byte to be sent from Array
for (j=0; j<8; j++) {
if ((*crc >> 7) ^ (currentByte&0x01)) // update CRC based result of XOR operation
{

*crc = (*crc << 1) ^ 0x07;

}
else
{

*crc = (*crc << 1);

}

currentByte = currentByte >> 1;

} // for CRC bit

} // for message byte
}

4.3 UART Signals

The UART interface on the TMC2209 uses a single bi-direction pin:

UART INTERFACE SIGNAL

PDN_UART

Non-inverted data input and output. I/O with Schmitt Trigger and VCC_IO level.

MS1_ADDR0

IC UART address bit 0 (LSB)

MS2_ADDR1

IC UART address bit 1

The IC checks PDN_UART for correctly received datagrams with its own address continuously. It adapts
to the baud rate based on the sync nibble, as described before. In case of a read access, it switches
on its output drivers and sends its response using the same baud rate. The output becomes switched
off four bit times after transfer of the last stop bit.

Master CPU

(µC with UART)

TMC22xx

different address

(R/W access)

PDN_UART

TXD

RXD

1k

Master CPU

(µC with UART)

TMC22xx #1

same address

(write only access)

PDN_UART

TXD

TMC22xx #2

same address

(write only access)

PDN_UART

TMC22xx

different address

(R/W access)

PDN_UART

MS2_AD1

MS1_AD0

MS2_AD1

MS1_AD0

+V

CCIO

Figure 4.1 Attaching the TMC2209 to a microcontroller UART

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 18

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4.4 Addressing Multiple Slaves

WRITE ONLY ACCESS

If read access is not used, and all slaves are to be programmed with the same initialization values, no
addressing is required. All slaves can be programmed in parallel like a single device (Figure 4.1.).

ADDRESSING MULTIPLE SLAVES

As the TMC2209 uses has a limited number of UART addresses, in principle only up to four ICs can be
accessed per UART interface channel. Adding analog switches allows separated access to more
individual ICs. This scheme is similar to an SPI bus with individual slave select lines (Figure 4.2). With
this scheme, the microstep resolution can be selected via MS1 and MS2 pins (consider actual setting
for addressing).

Master CPU

(µC with UART)

TMC22xx

#1

PDN_UART

TMC22xx

#2

TMC22xx

#3

TXD

RXD

+V

IO

1k

22k

SWO

¼ 74HC4066

Select#1Port pin

Port pin

Port pin

PDN_UART

+V

IO

22k

SWO

¼ 74HC4066

PDN_UART

+V

IO

22k

SWO

¼ 74HC4066

Select#2

Select#3

74HC1G125

Optional buffer for
transmission over long
lines or many slaves.

Port pin

Figure 4.2 Addressing multiple TMC2209 via single wire interface using analog switches

PROCEED AS FOLLOWS TO CONTROL MULTIPLE SLAVES:

- Set the UART to 8 bits, no parity. Select a baud rate safely within the valid range. At

250kBaud, a write access transmission requires 320µs (=8 Bytes * (8+2) bits * 4µs).

- Before starting an access, activate the select pin going to the analog switch by setting it high.

All other slaves select lines shall be off, unless a broadcast is desired.

- When using the optional buffer, set TMC2209 transmission send delay to an appropriate value

allowing the µC to switch off the buffer before receiving reply data.

- To start a transmission, activate the TXD line buffer by setting the control pin low.

- When sending a read access request, switch off the buffer after transmission of the last stop

bit is finished.

- Take into account, that all transmitted data also is received by the RXD input.

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5 Register Map

This chapter gives an overview of the complete register set. Some of the registers bundling a number
of single bits are detailed in extra tables. The functional practical application of the settings is detailed
in dedicated chapters.

Note

- Reset default: All registers become reset to 0 upon power up, unless otherwise noted.

- Add 0x80 to the address Addr for write accesses!

NOTATION OF HEXADECIMAL AND BINARY NUMBERS

0x

precedes a hexadecimal number, e.g. 0x04

%

precedes a multi-bit binary number, e.g. %100

NOTATION OF R/W FIELD

R

Read only

W

Write only

R/W

Read- and writable register

OVERVIEW REGISTER MAPPING

REGISTER

DESCRIPTION

General Configuration Registers

These registers contain

- global configuration

- global status flags

- OTP read access and programming

- interface configuration

Velocity Dependent Driver Feature Control Register
Set

This register set offers registers for

- driver current control, stand still reduction

- setting thresholds for different chopper modes

- internal pulse generator control

Chopper Register Set

This register set offers registers for

- optimization of StealthChop2 and SpreadCycle

and read out of internal values

- passive braking and freewheeling options

- driver diagnostics

- driver enable / disable

CoolStep and StallGuard Control Registers

These registers allow for

- Sensorless stall detection for homing

- Adaptive motor current control for best efficiency

UART

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5.1 General Registers

GENERAL CONFIGURATION REGISTERS (0X00…0X0F)

R/W

Addr

n

Register

Description / bit names

RW

0x00

10

GCONF

Bit

GCONF – Global configuration flags

0

I_scale_analog (Reset default=1)
0: Use internal reference derived from 5VOUT
1: Use voltage supplied to VREF as current reference

1

internal_Rsense (Reset default: OTP)
0: Operation with external sense resistors
1: Internal sense resistors. Use current supplied into

VREF as reference for internal sense resistor. VREF
pin internally is driven to GND in this mode.

2

en_SpreadCycle (Reset default: OTP)
0: StealthChop PWM mode enabled (depending on

velocity thresholds). Initially switch from off to

on state while in stand still, only.
1: SpreadCycle mode enabled
A high level on the pin SPREAD inverts this flag to
switch between both chopper modes.

3

shaft

1: Inverse motor direction

4

index_otpw

0: INDEX shows the first microstep position of

sequencer
1: INDEX pin outputs overtemperature prewarning

flag (otpw) instead

5

index_step

0: INDEX output as selected by index_otpw
1: INDEX output shows step pulses from internal

pulse generator (toggle upon each step)

6

pdn_disable

0: PDN_UART controls standstill current reduction
1: PDN_UART input function disabled. Set this bit,

when using the UART interface!

7

mstep_reg_select

0: Microstep resolution selected by pins MS1, MS2
1: Microstep resolution selected by MSTEP register

8

multistep_filt (Reset default=1)
0: No filtering of STEP pulses
1: Software pulse generator optimization enabled

when fullstep frequency > 750Hz (roughly). TSTEP

shows filtered step time values when active.

9

test_mode

0: Normal operation
1: Enable analog test output on pin ENN (pull down

resistor off), ENN treated as enabled.
IHOLD[1..0] selects the function of DCO:

0…2: T120, DAC, VDDH
Attention: Not for user, set to 0 for normal operation!

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 21

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GENERAL CONFIGURATION REGISTERS (0X00…0X0F)

R/W

Addr

n

Register

Description / bit names

R+

WC

0x01

3

GSTAT

Bit

GSTAT – Global status flags

(Re-Write with ‘1’ bit to clear respective flags)

0

reset

1: Indicates that the IC has been reset since the last

read access to GSTAT. All registers have been

cleared to reset values.

1

drv_err
1: Indicates, that the driver has been shut down

due to overtemperature or short circuit detection

since the last read access. Read DRV_STATUS for

details. The flag can only be cleared when all

error conditions are cleared.

2

uv_cp
1: Indicates an undervoltage on the charge pump.

The driver is disabled in this case. This flag is not

latched and thus does not need to be cleared.

R

0x02

8

IFCNT

Interface transmission counter. This register becomes
incremented with each successful UART interface write
access. Read out to check the serial transmission for
lost data. Read accesses do not change the content.

The counter wraps around from 255 to 0.

W

0x03

4

SLAVECONF

Bit

SLAVECONF

11..8

SENDDELAY for read access (time until reply is sent):
0, 1: 8 bit times
2, 3: 3*8 bit times
4, 5: 5*8 bit times
6, 7: 7*8 bit times
8, 9: 9*8 bit times
10, 11: 11*8 bit times
12, 13: 13*8 bit times

14, 15: 15*8 bit times

W

0x04

16

OTP_PROG

Bit

OTP_PROGRAM – OTP programming

Write access programs OTP memory (one bit at a time),
Read access refreshes read data from OTP after a write

2..0

OTPBIT
Selection of OTP bit to be programmed to the selected
byte location (n=0..7: programs bit n to a logic 1)

5..4

OTPBYTE

Selection of OTP programming location (0, 1 or 2)

15..8

OTPMAGIC

Set to 0xbd to enable programming. A programming
time of minimum 10ms per bit is recommended (check
by reading OTP_READ).

R

0x05

24

OTP_READ

Bit

OTP_READ (Access to OTP memory result and update)

See separate table!

7..0

OTP0 byte 0 read data

15..8

OTP1 byte 1 read data

23..16

OTP2 byte 2 read data

R

0x06

10

+ 8 IOIN

Bit

INPUT (Reads the state of all input pins available)

0

ENN

1

0

2

MS1

3

MS2

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 22

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GENERAL CONFIGURATION REGISTERS (0X00…0X0F)

R/W

Addr

n

Register

Description / bit names

4

DIAG

5 0 6

PDN_UART

7

STEP

8

SPREAD_EN

9

DIR

31..
24

VERSION: 0x21=first version of the IC
Identical numbers mean full digital compatibility.

RW

0x07

5+2

FACTORY_
CONF

4..0

FCLKTRIM (Reset default: OTP)
0…31: Lowest to highest clock frequency. Check at
charge pump output. The frequency span is not
guaranteed, but it is tested, that tuning to 12MHz
internal clock is possible. The devices come preset to
12MHz clock frequency by OTP programming.

9..8

OTTRIM (Default: OTP)
%00: OT=143°C, OTPW=120°C
%01: OT=150°C, OTPW=120°C
%10: OT=150°C, OTPW=143°C
%11: OT=157°C, OTPW=143°C

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 23

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5.1.1 OTP_READ – OTP configuration memory

The OTP memory holds power up defaults for certain registers. All OTP memory bits are cleared to 0
by default. Programming only can set bits, clearing bits is not possible. Factory tuning of the clock
frequency affects otp0.0 to otp0.4. The state of these bits therefore may differ between individual ICs.

0X05: OTP_READ – OTP MEMORY MAP

Bit

Name

Function

Comment

23

otp2.7

otp_en_SpreadCycle

This flag determines if the driver defaults to SpreadCycle
or to StealthChop.

0

Default: StealthChop (GCONF.en_SpreadCycle=0)
OTP 1.0 to 1.7 and 2.0 used for StealthChop
SpreadCycle settings: HEND=0; HSTART=5; TOFF=3

1

Default: SpreadCycle (GCONF.en_SpreadCycle=1)
OTP 1.0 to 1.7 and 2.0 used for SpreadCycle
StealthChop settings: PWM_GRAD=0; TPWM_THRS=0;
PWM_OFS=36; pwm_autograd=1

22

otp2.6

OTP_IHOLD

Reset default for standstill current IHOLD (used only if
current reduction enabled, e.g. pin PDN_UART low).
%00: IHOLD= 16 (53% of IRUN)
%01: IHOLD= 2 ( 9% of IRUN)
%10: IHOLD= 8 (28% of IRUN)
%11: IHOLD= 24 (78% of IRUN)
(Reset default for run current IRUN=31)

21

otp2.5

20

otp2.4

OTP_IHOLDDELAY

Reset default for IHOLDDELAY
%00: IHOLDDELAY= 1
%01: IHOLDDELAY= 2
%10: IHOLDDELAY= 4
%11: IHOLDDELAY= 8

19

otp2.3

18

otp2.2

otp_PWM_FREQ

Reset default for PWM_FREQ:
0: PWM_FREQ=%01=2/683
1: PWM_FREQ=%10=2/512

17

otp2.1

otp_PWM_REG

Reset default for PWM_REG:
0: PWM_REG=%1000: max. 4 increments / cycle
1: PWM_REG=%0010: max. 1 increment / cycle

16

otp2.0
otp_PWM_OFS

Depending on otp_en_SpreadCycle

0

0: PWM_OFS=36
1: PWM_OFS=00 (no feed forward scaling);
pwm_autograd=0

OTP_CHOPCONF8

1

Reset default for CHOPCONF.8 (hend1)

15

otp1.7

OTP_TPWMTHRS

Depending on otp_en_SpreadCycle

14

otp1.6

0

Reset default for TPWM_THRS as defined by (0..7):
0: TPWM_THRS= 0
1: TPWM_THRS= 200
2: TPWM_THRS= 300
3: TPWM_THRS= 400
4: TPWM_THRS= 500
5: TPWM_THRS= 800
6: TPWM_THRS= 1200
7: TPWM_THRS= 4000

13

otp1.5

OTP_CHOPCONF7...5

1

Reset default for CHOPCONF.5 to CHOPCONF.7
(hstrt1, hstrt2 and hend0)

12

otp1.4

otp_pwm_autograd

Depending on otp_en_SpreadCycle

0

0: pwm_autograd=1
1: pwm_autograd=0

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 24

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0X05: OTP_READ – OTP MEMORY MAP

Bit

Name

Function

Comment

OTP_CHOPCONF4

1

Reset default for CHOPCONF.4 (hstrt0);
(pwm_autograd=1)

11

otp1.3

OTP_PWM_GRAD

Depending on otp_en_SpreadCycle

10

otp1.2

0 Reset default for PWM_GRAD as defined by (0..15):
0: PWM_GRAD= 14
1: PWM_GRAD= 16
2: PWM_GRAD= 18
3: PWM_GRAD= 21
4: PWM_GRAD= 24
5: PWM_GRAD= 27
6: PWM_GRAD= 31
7: PWM_GRAD= 35
8: PWM_GRAD= 40
9: PWM_GRAD= 46
10: PWM_GRAD= 52
11: PWM_GRAD= 59
12: PWM_GRAD= 67
13: PWM_GRAD= 77
14: PWM_GRAD= 88
15: PWM_GRAD= 100

9

otp1.1

8

otp1.0

OTP_CHOPCONF3...0

1

Reset default for CHOPCONF.0 to CHOPCONF.3 (TOFF)

7

otp0.7

otp_TBL

Reset default for TBL:
0: TBL=%10
1: TBL=%01

6

otp0.6

otp_internalRsense

Reset default for GCONF.internal_Rsense
0: External sense resistors
1: Internal sense resistors

5

otp0.5

otp_OTTRIM

Reset default for OTTRIM:
0: OTTRIM= %00 (143°C)
1: OTTRIM= %01 (150°C)
(internal power stage temperature about 10°C above the
sensor temperature limit)

4

otp0.4

OTP_FCLKTRIM

Reset default for FCLKTRIM
0: lowest frequency setting
31: highest frequency setting

Attention: This value is pre-programmed by factory clock
trimming to the default clock frequency of 12MHz and
differs between individual ICs! It should not be altered.

3

otp0.3

2

otp0.2

1

otp0.1

0

otp0.0

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 25

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5.2 Velocity Dependent Control

VELOCITY DEPENDENT DRIVER FEATURE CONTROL REGISTER SET (0X10…0X1F)

R/W

Addr

n

Register

Description / bit names

W

0x10

5

+

5

+

4

IHOLD_IRUN

Bit

IHOLD_IRUN – Driver current control

4..0

IHOLD (Reset default: OTP)
Standstill current (0=1/32 … 31=32/32)
In combination with StealthChop mode, setting
IHOLD=0 allows to choose freewheeling or coil
short circuit (passive braking) for motor stand still.

12..8

IRUN (Reset default=31)
Motor run current (0=1/32 … 31=32/32)

Hint: Choose sense resistors in a way, that normal
IRUN is 16 to 31 for best microstep performance.

19..16

IHOLDDELAY (Reset default: OTP)
Controls the number of clock cycles for motor
power down after standstill is detected (stst=1) and
TPOWERDOWN has expired. The smooth transition
avoids a motor jerk upon power down.
0: instant power down

1..15: Delay per current reduction step in multiple
of 2^18 clocks

W

0x11

8

TPOWER
DOWN

TPOWERDOWN (Reset default=20)

Sets the delay time from stand still (stst) detection to motor
current power down. Time range is about 0 to 5.6 seconds.

0…((2^8)-1) * 2^18 t

CLK

Attention: A minimum setting of 2 is required to allow
automatic tuning of StealthChop PWM_OFFS_AUTO.

R

0x12

20

TSTEP

Actual measured time between two 1/256 microsteps derived
from the step input frequency in units of 1/fCLK. Measured
value is (2^20)-1 in case of overflow or stand still.

The TSTEP related threshold uses a hysteresis of 1/16 of the
compare value to compensate for jitter in the clock or the step
frequency: (Txxx*15/16)-1 is the lower compare value for each
TSTEP based comparison.
This means, that the lower switching velocity equals the
calculated setting, but the upper switching velocity is higher as
defined by the hysteresis setting.

W

0x13

20

TPWMTHRS

Sets the upper velocity for StealthChop voltage PWM mode.
TSTEP ≥ TPWMTHRS

- StealthChop PWM mode is enabled, if configured

When the velocity exceeds the limit set by TPWMTHRS, the
driver switches to SpreadCycle.
0: Disabled

W

0x22

24

VACTUAL

VACTUAL allows moving the motor by UART control.

It gives the motor velocity in +-(2^23)-1 [µsteps / t]
0: Normal operation. Driver reacts to STEP input.
/=0: Motor moves with the velocity given by VACTUAL. Step
pulses can be monitored via INDEX output. The motor
direction is controlled by the sign of VACTUAL.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 26

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5.3 StallGuard Control

COOLSTEP AND STALLGUARD CONTROL REGISTER SET (0X14, 0X40…0X42)

R/W

Addr

n

Register

Description / bit names

W

0x14

20

TCOOLTHRS

TCOOLTHRS

This is the lower threshold velocity for switching on smart
energy CoolStep and StallGuard to DIAG output. (unsigned)
Set this parameter to disable CoolStep at low speeds, where it
cannot work reliably. The stall output signal become enabled
when exceeding this velocity. It becomes disabled again once
the velocity falls below this threshold.
TCOOLTHRS ≥ TSTEP > TPWMTHRS

- CoolStep is enabled, if configured (only with StealthChop)

- Stall output signal on pin DIAG is enabled

W

0x40

8

SGTHRS

SGTHRS

Detection threshold for stall. The StallGuard value SG_RESULT
becomes compared to the double of this threshold.
A stall is signaled with
SG_RESULT ≤ SGTHRS*2

R

0x41

10

SG_RESULT

StallGuard result. SG_RESULT becomes updated with each
fullstep, independent of TCOOLTHRS and SGTHRS. A higher
value signals a lower motor load and more torque headroom.
Intended for StealthChop mode, only. Bits 9 and 0 will always
show 0. Scaling to 10 bit is for compatibility to StallGuard2.

W

0x42

16

COOLCONF

CoolStep configuration

See separate table!

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 27

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5.3.1 COOLCONF – Smart Energy Control CoolStep

0X42: COOLCONF – SMART ENERGY CONTROL COOLSTEP AND STALLGUARD

Bit

Name

Function

Comment

…

15

seimin

minimum current for
smart current control

0: 1/2 of current setting (IRUN)
Attention: use with IRUN≥10
1: 1/4 of current setting (IRUN)
Attention: use with IRUN≥20

14

sedn1

current down step
speed

%00: For each 32 StallGuard4 values decrease by one
%01: For each 8 StallGuard4 values decrease by one
%10: For each 2 StallGuard4 values decrease by one
%11: For each StallGuard4 value decrease by one

13

sedn0

12 - reserved

set to 0

11

semax3

StallGuard hysteresis
value for smart current
control

If the StallGuard4 result is equal to or above
(SEMIN+SEMAX+1)*32, the motor current becomes
decreased to save energy.
%0000 … %1111: 0 … 15

10

semax2

9

semax1

8

semax0

7 - reserved

set to 0

6

seup1

current up step width

Current increment steps per measured StallGuard value
%00 … %11: 1, 2, 4, 8

5

seup0

4 - reserved

set to 0

3

semin3

minimum StallGuard
value for smart current
control and
smart current enable

If the StallGuard4 result falls below SEMIN*32, the motor
current becomes increased to reduce motor load angle.
%0000: smart current control CoolStep off
%0001 … %1111: 1 … 15

2

semin2

1

semin1

0

semin0

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 28

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5.4 Sequencer Registers

The sequencer registers have a pure informative character and are read-only. They help for special
cases like storing the last motor position before power off in battery powered applications.

MICROSTEPPING CONTROL REGISTER SET (0X60…0X6B)

R/W

Addr

n

Register

Description / bit names

Range [Unit]

R

0x6A

10

MSCNT

Microstep counter. Indicates actual position
in the microstep table for CUR_A. CUR_B uses
an offset of 256 into the table. Reading out
MSCNT allows determination of the motor
position within the electrical wave.

0…1023

R

0x6B

9

+ 9 MSCURACT

bit 8… 0: CUR_A (signed):
Actual microstep current for

motor phase A as read from the
internal sine wave table (not

scaled by current setting)
bit 24… 16: CUR_B (signed):
Actual microstep current for

motor phase B as read from the

internal sine wave table (not

scaled by current setting)

+/-0...255

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 29

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5.5 Chopper Control Registers

DRIVER REGISTER SET (0X6C…0X7F)

R/W

Addr

n

Register

Description / bit names

Range [Unit]

RW

0x6C

32

CHOPCONF

Chopper and driver configuration

See separate table!

Reset default=
0x10000053

R

0x6F

32

DRV_
STATUS

Driver status flags and current level read
back

See separate table!

RW

0x70

22

PWMCONF

StealthChop PWM chopper configuration

See separate table!

Reset default=
0xC10D0024

R

0x71

9+8

PWM_SCALE

Results of StealthChop amplitude regulator.
These values can be used to monitor
automatic PWM amplitude scaling (255=max.
voltage).

bit 7… 0

PWM_SCALE_SUM:
Actual PWM duty cycle. This
value is used for scaling the
values CUR_A and CUR_B read
from the sine wave table.

0…255

bit 24… 16

PWM_SCALE_AUTO:
9 Bit signed offset added to the
calculated PWM duty cycle. This
is the result of the automatic
amplitude regulation based on
current measurement.

signed

-255…+255

R

0x72

8+8

PWM_AUTO

These automatically generated values can be
read out in order to determine a default /
power up setting for PWM_GRAD and
PWM_OFS.

bit 7… 0

PWM_OFS_AUTO:
Automatically determined offset
value

0…255

bit 23… 16

PWM_GRAD_AUTO:
Automatically determined
gradient value

0…255

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 30

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5.5.1 CHOPCONF – Chopper Configuration

0X6C: CHOPCONF – CHOPPER CONFIGURATION

Bit

Name

Function

Comment

31

diss2vs

Low side short
protection disable

0: Short protection low side is on
1: Short protection low side is disabled

30

diss2g

short to GND
protection disable

0: Short to GND protection is on
1: Short to GND protection is disabled

29

dedge

enable double edge
step pulses

1: Enable step impulse at each step edge to reduce step
frequency requirement. This mode is not compatible
with the step filtering function (multistep_filt)

28

intpol

interpolation to 256
microsteps

1: The actual microstep resolution (MRES) becomes
extrapolated to 256 microsteps for smoothest motor
operation.
(Default: 1)

27

mres3

MRES

micro step resolution

%0000:
Native 256 microstep setting.

26

mres2

25

mres1

%0001 … %1000:
128, 64, 32, 16, 8, 4, 2, FULLSTEP

Reduced microstep resolution.
The resolution gives the number of microstep entries per
sine quarter wave.
When choosing a lower microstep resolution, the driver
automatically uses microstep positions which result in a
symmetrical wave.

Number of microsteps per step pulse = 2^MRES
(Selection by pins unless disabled by GCONF.
mstep_reg_select)

24

mres0

23

-

reserved

set to 0

22

21

20

19

18

17

vsense

sense resistor voltage
based current scaling

0: Low sensitivity, high sense resistor voltage
1: High sensitivity, low sense resistor voltage

16

tbl1

TBL

blank time select

%00 … %11:
Set comparator blank time to 16, 24, 32 or 40 clocks
Hint: %00 or %01 is recommended for most applications
(Default: OTP)

15

tbl0

14

-

reserved

set to 0

13

12

11

10

hend3

HEND

hysteresis low value

OFFSET

sine wave offset

%0000 … %1111:
Hysteresis is -3, -2, -1, 0, 1, …, 12
(1/512 of this setting adds to current setting)
This is the hysteresis value which becomes used for the
hysteresis chopper.
(Default: OTP, resp. 5 in StealthChop mode)

9

hend2

8

hend1

7

hend0

6

hstrt2

HSTRT

hysteresis start value
added to HEND

%000 … %111:
Add 1, 2, …, 8 to hysteresis low value HEND

(1/512 of this setting adds to current setting)

Attention: Effective HEND+HSTRT ≤ 16.
Hint: Hysteresis decrement is done each 16 clocks

5

hstrt1

4

hstrt0

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 31

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0X6C: CHOPCONF – CHOPPER CONFIGURATION

Bit

Name

Function

Comment

(Default: OTP, resp. 0 in StealthChop mode)

3

toff3

TOFF off time

and driver enable

Off time setting controls duration of slow decay phase
N

CLK

= 24 + 32*TOFF
%0000: Driver disable, all bridges off
%0001: 1 – use only with TBL ≥ 2
%0010 … %1111: 2 … 15
(Default: OTP, resp. 3 in StealthChop mode)

2

toff2

1

toff1

0

toff0

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 32

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5.5.2 PWMCONF – Voltage PWM Mode StealthChop

0X70: PWMCONF – VOLTAGE MODE PWM STEALTHCHOP

Bit

Name

Function

Comment

31

PWM_LIM

PWM automatic scale
amplitude limit when
switching on

Limit for PWM_SCALE_AUTO when switching back from
SpreadCycle to StealthChop. This value defines the upper
limit for bits 7 to 4 of the automatic current control
when switching back. It can be set to reduce the current
jerk during mode change back to StealthChop.
It does not limit PWM_GRAD or PWM_GRAD_AUTO offset.
(Default = 12)

30

29

28

27

PWM_REG

Regulation loop
gradient

User defined maximum PWM amplitude change per half
wave when using pwm_autoscale=1. (1…15):
1: 0.5 increments (slowest regulation)
2: 1 increment (default with OTP2.1=1)
3: 1.5 increments
4: 2 increments
…
8: 4 increments (default with OTP2.1=0)
...
15: 7.5 increments (fastest regulation)

26

25

24

23 - reserved

set to 0

22 - reserved

set to 0

21

freewheel1

Allows different
standstill modes

Stand still option when motor current setting is zero
(I_HOLD=0).
%00: Normal operation
%01: Freewheeling
%10: Coil shorted using LS drivers
%11: Coil shorted using HS drivers

20

freewheel0

19

pwm_
autograd

PWM automatic
gradient adaptation

0

Fixed value for PWM_GRAD
(PWM_GRAD_AUTO = PWM_GRAD)

1

Automatic tuning (only with pwm_autoscale=1)
PWM_GRAD_AUTO is initialized with PWM_GRAD
and becomes optimized automatically during
motion.
Preconditions

1. PWM_OFS_AUTO has been automatically

initialized. This requires standstill at IRUN for
>130ms in order to a) detect standstill b) wait >
128 chopper cycles at IRUN and c) regulate
PWM_OFS_AUTO so that

-1 < PWM_SCALE_AUTO < 1

2. Motor running and 1.5 * PWM_OFS_AUTO <

PWM_SCALE_SUM < 4* PWM_OFS_AUTO and
PWM_SCALE_SUM < 255.

Time required for tuning PWM_GRAD_AUTO
About 8 fullsteps per change of +/-1.

18

pwm_
autoscale

PWM automatic
amplitude scaling

0

User defined feed forward PWM amplitude. The
current settings IRUN and IHOLD have no influence!
The resulting PWM amplitude (limited to 0…255) is:

PWM_OFS * ((CS_ACTUAL+1) / 32)

+ PWM_GRAD * 256 / TSTEP

1

Enable automatic current control (Reset default)

17

pwm_freq1

PWM frequency

%00: f

PWM

=2/1024 f

CLK

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 33

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0X70: PWMCONF – VOLTAGE MODE PWM STEALTHCHOP

Bit

Name

Function

Comment

16

pwm_freq0

selection

%01: f

PWM

=2/683 f

CLK

%10: f

PWM

=2/512 f

CLK

%11: f

PWM

=2/410 f

CLK

15

PWM_
GRAD

User defined amplitude
gradient

Velocity dependent gradient for PWM amplitude:
PWM_GRAD * 256 / TSTEP
This value is added to PWM_AMPL to compensate for
the velocity-dependent motor back-EMF.

With automatic scaling (pwm_autoscale=1) the value is
used for first initialization, only. Set PWM_GRAD to the
application specific value (it can be read out from
PWM_GRAD_AUTO) to speed up the automatic tuning
process. An approximate value can be stored to OTP by
programming OTP_PWM_GRAD.

14

13

12

11

10

9

8

7

PWM_
OFS

User defined amplitude
(offset)

User defined PWM amplitude offset (0-255) related to full
motor current (CS_ACTUAL=31) in stand still.
(Reset default=36)

When using automatic scaling (pwm_autoscale=1) the
value is used for initialization, only. The autoscale
function starts with PWM_SCALE_AUTO=PWM_OFS and
finds the required offset to yield the target current
automatically.

PWM_OFS = 0 will disable scaling down motor current
below a motor specific lower measurement threshold.
This setting should only be used under certain
conditions, i.e. when the power supply voltage can vary
up and down by a factor of two or more. It prevents
the motor going out of regulation, but it also prevents
power down below the regulation limit.

PWM_OFS > 0 allows automatic scaling to low PWM duty
cycles even below the lower regulation threshold. This
allows low (standstill) current settings based on the
actual (hold) current scale (register IHOLD_IRUN).

6

5 4 3

2

1

0

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 34

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5.5.3 DRV_STATUS – Driver Status Flags

0X6F: DRV_STATUS – DRIVER STATUS FLAGS AND CURRENT LEVEL READ BACK

Bit

Name

Function

Comment

31

stst

standstill indicator

This flag indicates motor stand still in each operation
mode. This occurs 2^20 clocks after the last step pulse.

30

stealth

StealthChop indicator

1: Driver operates in StealthChop mode
0: Driver operates in SpreadCycle mode

29

-

reserved

Ignore these bits.

28

27

26

25

24

23

-

reserved

Ignore these bits.

22

21

20

CS_
ACTUAL

actual motor current /
smart energy current

Actual current control scaling, for monitoring the
function of the automatic current scaling.

19

18

17

16

15

-

reserved

Ignore these bits.

14

13

12

11

t157

157°C comparator

1: Temperature threshold is exceeded

10

t150

150°C comparator

1: Temperature threshold is exceeded

9

t143

143°C comparator

1: Temperature threshold is exceeded

8

t120

120°C comparator

1: Temperature threshold is exceeded

7

olb

open load indicator
phase B

1: Open load detected on phase A or B.
Hint: This is just an informative flag. The driver takes no
action upon it. False detection may occur in fast motion
and standstill. Check during slow motion, only.

6

ola

open load indicator
phase A

5

s2vsb

low side short
indicator phase B

1: Short on low-side MOSFET detected on phase A or B.
The driver becomes disabled. The flags stay active, until
the driver is disabled by software (TOFF=0) or by the
ENN input. Flags are separate for both chopper modes.

4

s2vsa

low side short
indicator phase A

3

s2gb

short to ground
indicator phase B

1: Short to GND detected on phase A or B. The driver
becomes disabled. The flags stay active, until the driver
is disabled by software (TOFF=0) or by the ENN input.
Flags are separate for both chopper modes.

2

s2ga

short to ground
indicator phase A

1

ot

overtemperature flag

1: The selected overtemperature limit has been reached.
Drivers become disabled until otpw is also cleared due
to cooling down of the IC.
The overtemperature flag is common for both bridges.

0

otpw

overtemperature pre­warning flag

1: The selected overtemperature pre-warning threshold
is exceeded.
The overtemperature pre-warning flag is common for
both bridges.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 35

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6 StealthChop™

StealthChop is an extremely quiet mode of operation for stepper motors. It is based on a
voltage mode PWM. In case of standstill and at low velocities, the motor is absolutely
noiseless. Thus, StealthChop operated stepper motor applications are very suitable for
indoor or home use. The motor operates absolutely free of vibration at low velocities.

With StealthChop, the motor current is applied by driving a certain effective voltage into
the coil, using a voltage mode PWM. With the enhanced StealthChop2, the driver automatically adapts
to the application for best performance. No more configurations are required. Optional configuration
allows for tuning the setting in special cases, or for storing initial values for the automatic adaptation
algorithm. For high velocity consider SpreadCycle in combination with StealthChop.

Figure 6.1 Motor coil sine wave current with StealthChop (measured with current probe)

6.1 Automatic Tuning

StealthChop2 integrates an automatic tuning procedure (AT), which adapts the most important
operating parameters to the motor automatically. This way, StealthChop2 allows high motor dynamics
and supports powering down the motor to very low currents. Just two steps have to be respected by
the motion controller for best results: Start with the motor in standstill, but powered with nominal
run current (AT#1). Move the motor at a medium velocity, e.g. as part of a homing procedure (AT#2).
Figure 6.2 shows the tuning procedure.
Border conditions in for AT#1 and AT#2 are shown in the following table:

AUTOMATIC TUNING TIMING AND BORDER CONDITIONS

Step

Parameter

Conditions

Duration

AT#1

PWM_
OFS_AUTO

- Motor in standstill and actual current scale (CS) is

identical to run current (IRUN).

- If standstill reduction is enabled (pin PDN_UART=0),

an initial step pulse switches the drive back to run
current.

- Pins VS and VREF at operating level.

≤ 2^20+2*2^18 t

CLK

,
≤ 130ms
(with internal clock)

AT#2

PWM_
GRAD_AUTO

- Motor must move at a velocity, where a significant

amount of back EMF is generated and where the full
run current can be reached. Conditions:

- 1.5 * PWM_OFS_AUTO < PWM_SCALE_SUM <

4 * PWM_OFS_AUTO

- PWM_SCALE_SUM < 255.

Hint: A typical range is 60-300 RPM. Determine best
conditions with the evaluation board and monitor
PWM_SCALE_AUTO going down to zero during tuning.

8 fullsteps are required
for a change of +/-1.
For a typical motor with
PWM_GRAD_AUTO
optimum at 64 or less, up
to 400 fullsteps are
required when starting
from OTP default 14.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 36

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AT#1

Stand still

AT#2

Homing

Ready

Power Up

stealthChop2 regulates to nominal

current and stores result to

PWM_OFS_AUTO

(Requires stand still for >130ms)

N

PWM_GRAD_AUTO becomes

initialized by OTP

Driver Enabled? N

Standstill re-

duction enabled?

Y

Issue (at least) a single step

pulse and stop again, to

power motor to run current

Y

Driver Enabled? N

Y

Move the motor, e.g. for homing.

Include a constant, medium velocity

ramp segment.

Store PWM_GRAD_AUTO or

write to OTP for faster

tuning procedure

Option with UART

PWM_

GRAD_AUTO stored

in OTP?

N

Y

stealthChop2 regulates to nominal

current and optimizes PWM_GRAD_AUTO

(requires 8 fullsteps per change of 1,

typically a few 100 fullsteps in sum)

stealthChop2 settings are optimized!

stealthChop2 keeps tuning during

subsequent motion and stand still periods

adapting to motor heating, supply

variations, etc.

Figure 6.2 StealthChop2 automatic tuning procedure

Attention
Modifying VREF or the supply voltage VS invalidates the result of the automatic tuning process. Motor
current regulation cannot compensate significant changes until next AT#1 phase. Automatic tuning
adapts to changed conditions whenever AT#1 and AT#2 conditions are fulfilled in the later operation.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 37

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6.2 StealthChop Options

In order to match the motor current to a certain level, the effective PWM voltage becomes scaled
depending on the actual motor velocity. Several additional factors influence the required voltage level
to drive the motor at the target current: The motor resistance, its back EMF (i.e. directly proportional
to its velocity) as well as the actual level of the supply voltage. Two modes of PWM regulation are
provided: The automatic tuning mode (AT) using current feedback (pwm_autoscale = 1, pwm_autograd
= 1) and a feed forward velocity-controlled mode (pwm_autoscale = 0). The feed forward velocity­controlled mode will not react to a change of the supply voltage or to events like a motor stall, but it
provides very stable amplitude. It does not use nor require any means of current measurement. This
is perfect when motor type and supply voltage are well known. Therefore, we recommend the
automatic mode, unless current regulation is not satisfying in the given operating conditions.

It is recommended to operate in automatic tuning mode.

Non-automatic mode (pwm_autoscale=0) should be considered only with well-known motor and
operating conditions. In this case, programming via the UART interface is required. The operating
parameters PWM_GRAD and PWM_OFS can be determined in automatic tuning mode initially.

Hint: In non-automatic mode the power supply current directly reflects mechanical load on the motor.

The StealthChop PWM frequency can be chosen in four steps in order to adapt the frequency divider
to the frequency of the clock source. A setting in the range of 20-50kHz is good for most applications.
It balances low current ripple and good higher velocity performance vs. dynamic power dissipation.

CHOICE OF PWM FREQUENCY FOR STEALTHCHOP

Clock frequency
f

CLK

PWM_FREQ=%00

f

PWM

=2/1024 f

CLK

PWM_FREQ=%01
f

PWM

=2/683 f

CLK

(default)

PWM_FREQ=%10

f

PWM

=2/512 f

CLK

(OTP option)

PWM_FREQ=%11

f

PWM

=2/410 f

CLK

18MHz

35.2kHz

52.7kHz

70.3kHz

87.8kHz

16MHz

31.3kHz

46.9kHz

62.5kHz

78.0kHz

12MHz (internal)

23.4kHz

35.1kHz

46.9kHz

58.5kHz

10MHz

19.5kHz

29.3kHz

39.1kHz

48.8kHz

8MHz

15.6kHz

23.4kHz

31.2kHz

39.0kHz

Table 6.1 Choice of PWM frequency – green / light green: recommended

6.3 StealthChop Current Regulator

In StealthChop voltage PWM mode, the autoscaling function (pwm_autoscale = 1, pwm_autograd = 1)
regulates the motor current to the desired current setting. Automatic scaling is used as part of the
automatic tuning process (AT), and for subsequent tracking of changes within the motor parameters.
The driver measures the motor current during the chopper on time and uses a proportional regulator
to regulate PWM_SCALE_AUTO in order match the motor current to the target current. PWM_REG is the
proportionality coefficient for this regulator. Basically, the proportionality coefficient should be as
small as possible in order to get a stable and soft regulation behavior, but it must be large enough to
allow the driver to quickly react to changes caused by variation of the motor target current (e.g.
change of VREF). During initial tuning step AT#2, PWM_REG also compensates for the change of motor
velocity. Therefore, a high acceleration during AT#2 will require a higher setting of PWM_REG. With
careful selection of homing velocity and acceleration, a minimum setting of the regulation gradient
often is sufficient (PWM_REG=1). PWM_REG setting should be optimized for the fastest required
acceleration and deceleration ramp (compare Figure 6.3 and Figure 6.4). The quality of the setting

PWM_REG in phase AT#2 and the finished automatic tuning procedure (or non-automatic settings for
PWM_OFS and PWM_GRAD) can be examined when monitoring motor current during an acceleration

phase Figure 6.5.

UART

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 38

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Figure 6.3 Scope shot: good setting for PWM_REG

Figure 6.4 Scope shot: too small setting for PWM_REG during AT#2

Motor Velocity

Time

Stand still

PWM scale

PWM reaches max. amplitude

255

0

Motor Current

Nominal Current
(sine wave RMS)

RMS current constant

(IRUN)

0

PWM scale

Current may drop due

to high velocity

PWM

_

GRAD

(

_

AUTO

)

ok

PWM

_

GRAD

(

_

AUTO

)

ok

PWM_OFS_(AUTO) ok

(

PWM

_

REG

during AT

#

2

ok

)

IHOLD

PWM_OFS_(AUTO) ok

Figure 6.5 Successfully determined PWM_GRAD(_AUTO) and PWM_OFS(_AUTO)

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 39

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Quick Start

For a quick start, see the Quick Configuration Guide in chapter 16.

6.3.1 Lower Current Limit

The StealthChop current regulator imposes a lower limit for motor current regulation. As the coil
current can be measured in the shunt resistor during chopper on phase only, a minimum chopper
duty cycle allowing coil current regulation is given by the blank time as set by TBL and by the
chopper frequency setting. Therefore, the motor specific minimum coil current in StealthChop
autoscaling mode rises with the supply voltage and with the chopper frequency. A lower blanking
time allows a lower current limit. It is important for the correct determination of PWM_OFS_AUTO,
that in AT#1 the run current set by the sense resistor, VREF and IRUN is well within the regulation
range. Lower currents (e.g. for standstill power down) are automatically realized based on
PWM_OFS_AUTO and PWM_GRAD_AUTO respectively based on PWM_OFS and PWM_GRAD with non­automatic current scaling. The freewheeling option allows going to zero motor current.

Lower motor coil current limit for StealthChop2 automatic tuning:





 













With VM the motor supply voltage and R

COIL

the motor coil resistance.

I

Lower Limit

can be treated as a thumb value for the minimum nominal IRUN motor current setting.

EXAMPLE:

A motor has a coil resistance of 5Ω, the supply voltage is 24V. With TBL=%01 and PWM_FREQ=%00,
t

BLANK

is 24 clock cycles, f

PWM

is 2/(1024 clock cycles):



































 

This means, the motor target current for automatic tuning must be 225mA or more, taking into
account all relevant settings. This lower current limit also applies for modification of the motor
current via the analog input VREF.

Attention

For automatic tuning, a lower coil current limit applies. The motor current in automatic tuning phase
AT#1 must exceed this lower limit. I

LOWER LIMIT

can be calculated or measured using a current probe.
Setting the motor run-current or hold-current below the lower current limit during operation by
modifying IRUN and IHOLD is possible after successful automatic tuning.
With StealthChop, ensure that IRUN is in the range 8 to 31. Set vsense to yield lower current setting!

The lower current limit also limits the capability of the driver to respond to changes of VREF.

6.4 Velocity Based Scaling

Velocity based scaling scales the StealthChop amplitude based on the time between each two steps,
i.e. based on TSTEP, measured in clock cycles. This concept basically does not require a current
measurement, because no regulation loop is necessary. A pure velocity-based scaling is available via
UART programming, only, when setting pwm_autoscale = 0. The basic idea is to have a linear
approximation of the voltage required to drive the target current into the motor. The stepper motor
has a certain coil resistance and thus needs a certain voltage amplitude to yield a target current

UART

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 40

www.trinamic.com

based on the basic formula I=U/R. With R being the coil resistance, U the supply voltage scaled by the
PWM value, the current I results. The initial value for PWM_AMPL can be calculated:



  



 







With VM the motor supply voltage and I

COIL

the target RMS current

The effective PWM voltage U

PWM

(1/SQRT(2) x peak value) results considering the 8 bit resolution and

248 sine wave peak for the actual PWM amplitude shown as PWM_SCALE:





 


















 





With rising motor velocity, the motor generates an increasing back EMF voltage. The back EMF voltage
is proportional to the motor velocity. It reduces the PWM voltage effective at the coil resistance and
thus current decreases. The TMC2209 provides a second velocity dependent factor (PWM_GRAD) to
compensate for this. The overall effective PWM amplitude (PWM_SCALE_SUM) in this mode
automatically is calculated in dependence of the microstep frequency as:

     











With f

STEP

being the microstep frequency for 256 microstep resolution equivalent

and f

CLK

the clock frequency supplied to the driver or the actual internal frequency

As a first approximation, the back EMF subtracts from the supply voltage and thus the effective current
amplitude decreases. This way, a first approximation for PWM_GRAD setting can be calculated:





󰇯







󰇰   





 

 

C

BEMF

is the back EMF constant of the motor in Volts per radian/second.
MSPR is the number of microsteps per rotation, e.g. 51200 = 256µsteps multiplied by 200 fullsteps for
a 1.8° motor.

PWM scaling

(PWM_SCALE_SUM)

Velocity

PWM_OFS

PWM reaches
max. amplitude

255

0

PWM

_

GRAD

Motor current

Nominal current

(e.g. sine wave RMS)

Current drops

(

depends on

motor load

)

Constant motor

RMS current

0

V

PWMMAX

Figure 6.6 Velocity based PWM scaling (pwm_autoscale=0)

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 41

www.trinamic.com

Hint
The values for PWM_OFS and PWM_GRAD can easily be optimized by tracing the motor current with a
current probe on the oscilloscope. Alternatively, automatic tuning determines these values and they
can be read out from PWM_OFS_AUTO and PWM_GRAD_AUTO.

UNDERSTANDING THE BACK EMF CONSTANT OF A MOTOR

The back EMF constant is the voltage a motor generates when turned with a certain velocity. Often
motor datasheets do not specify this value, as it can be deducted from motor torque and coil current
rating. Within SI units, the numeric value of the back EMF constant C

BEMF

has the same numeric value
as the numeric value of the torque constant. For example, a motor with a torque constant of 1 Nm/A
would have a C

BEMF

of 1V/rad/s. Turning such a motor with 1 rps (1 rps = 1 revolution per second =

6.28 rad/s) generates a back EMF voltage of 6.28V. Thus, the back EMF constant can be calculated as:











 

󰇟

󰇠

  



󰇟󰇠

I

COILNOM

is the motor’s rated phase current for the specified holding torque

HoldingTorque is the motor specific holding torque, i.e. the torque reached at I

COILNOM

on both coils.
The torque unit is [Nm] where 1Nm = 100Ncm = 1000mNm.
The BEMF voltage is valid as RMS voltage per coil, thus the nominal current has a factor of 2 in this
formula.

6.5 Combine StealthChop and SpreadCycle

For applications requiring high velocity motion, SpreadCycle may bring more stable operation in the
upper velocity range. To combine no-noise operation with highest dynamic performance, the TMC2209
allows combining StealthChop and SpreadCycle based on a velocity threshold (Figure 6.7). A velocity
threshold (TPWMTHRS) can be preprogrammed to OTP to support this mode even in standalone
operation. With this, StealthChop is only active at low velocities.

Running low speed

optionoption

Running low speed

Running high speed

motor stand still

motor going to standby

motor in standby

motor in standby

v

t

TSTEP < TPWMTHRS*16/16

TSTEP > TPWMTHRS

0

VACTUAL
~1/TSTEP

current

TPOWERDOWN

RMS current

I_HOLD

I_RUN

dI * IHOLDDELAY

stealthChop

spreadCycle

Chopper mode

TRINAMIC, B. Dwersteg, 14.3.14

Figure 6.7 TPWMTHRS for optional switching to SpreadCycle

UART OTP

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 42

www.trinamic.com

As a first step, both chopper principles should be parameterized and optimized individually
(SpreadCycle settings may be programmed to OTP memory). In a next step, a transfer velocity has to
be fixed. For example, StealthChop operation is used for precise low speed positioning, while
SpreadCycle shall be used for highly dynamic motion. TPWMTHRS determines the transition velocity.
Read out TSTEP when moving at the desired velocity and program the resulting value to TPWMTHRS.
Use a low transfer velocity to avoid a jerk at the switching point.

A jerk occurs when switching at higher velocities, because the back-EMF of the motor (which rises
with the velocity) causes a phase shift of up to 90° between motor voltage and motor current. So
when switching at higher velocities between voltage PWM and current PWM mode, this jerk will occur
with increased intensity. A high jerk may even produce a temporary overcurrent condition (depending
on the motor coil resistance). At low velocities (e.g. 1 to a few 10 RPM), it can be completely
neglected for most motors. Therefore, consider the switching jerk when choosing TPWMTHRS. Set
TPWMTHRS zero if you want to work with StealthChop only.

When enabling the StealthChop mode the first time using automatic current regulation, the motor
must be at stand still in order to allow a proper current regulation. When the drive switches to
StealthChop at a higher velocity, StealthChop logic stores the last current regulation setting until the
motor returns to a lower velocity again. This way, the regulation has a known starting point when
returning to a lower velocity, where StealthChop becomes re-enabled. Therefore, neither the velocity
threshold nor the supply voltage must be considerably changed during the phase while the chopper
is switched to a different mode, because otherwise the motor might lose steps or the instantaneous
current might be too high or too low.

A motor stall or a sudden change in the motor velocity may lead to the driver detecting a short
circuit or to a state of automatic current regulation, from which it cannot recover. Clear the error flags
and restart the motor from zero velocity to recover from this situation.

Hint

Start the motor from standstill when switching on StealthChop the first time and keep it stopped for
at least 128 chopper periods to allow StealthChop to do initial standstill current control.

6.6 Flags in StealthChop

As StealthChop uses voltage mode driving, status flags based on current measurement respond
slower, respectively the driver reacts delayed to sudden changes of back EMF, like on a motor stall.

Attention

A motor stall, or abrupt stop of the motion during operation in StealthChop can trigger an
overcurrent condition. Depending on the previous motor velocity, and on the coil resistance of the
motor, it significantly increases motor current for a time of several 10ms. With low velocities, where
the back EMF is just a fraction of the supply voltage, there is no danger of triggering the short
detection. When homing using StallGuard4 to stop the motor upon stall, this is basically avoided.

6.6.1 Open Load Flags

In StealthChop mode, status information is different from the cycle-by-cycle regulated SpreadCycle
mode. OLA and OLB show if the current regulation sees that the nominal current can be reached on
both coils.

- A flickering OLA or OLB can result from asymmetries in the sense resistors or in the motor

coils.

- An interrupted motor coil leads to a continuously active open load flag for the coil.

- One or both flags are active, if the current regulation did not succeed in scaling up to the full

target current within the last few fullsteps (because no motor is attached or a high velocity
exceeds the PWM limit).

If desired, do an on-demand open load test using the SpreadCycle chopper, as it delivers the safest
result. With StealthChop, PWM_SCALE_SUM can be checked to detect the correct coil resistance.

UART

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 43

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6.6.2 PWM_SCALE_SUM Informs about the Motor State

Information about the motor state is available with automatic scaling by reading out
PWM_SCALE_SUM. As this parameter reflects the actual voltage required to drive the target current into
the motor, it depends on several factors: motor load, coil resistance, supply voltage, and current
setting. Therefore, an evaluation of the PWM_SCALE_SUM value allows checking the motor operation
point. When reaching the limit (255), the current regulator cannot sustain the full motor current, e.g.
due to a drop in supply volage.

6.7 Freewheeling and Passive Braking

StealthChop provides different options for motor standstill. These options can be enabled by setting
the standstill current IHOLD to zero and choosing the desired option using the FREEWHEEL setting.
The desired option becomes enabled after a time period specified by TPOWERDOWN and
IHOLD_DELAY. Current regulation becomes frozen once the motor target current is at zero current in
order to ensure a quick startup. With the freewheeling options, both freewheeling and passive
braking can be realized. Passive braking is an effective eddy current motor braking, which consumes a
minimum of energy, because no active current is driven into the coils. However, passive braking will
allow slow turning of the motor when a continuous torque is applied.

Hint

Operate the motor within your application when exploring StealthChop. Motor performance often is
better with a mechanical load, because it prevents the motor from stalling due mechanical oscillations
which can occur without load.

UART

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 44

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PARAMETERS RELATED TO STEALTHCHOP

Parameter

Description

Setting

Comment

en_spread_
cycle

General disable for use of StealthChop (register
GCONF). The input SPREAD is XORed to this flag.

1

Do not use StealthChop

0

StealthChop enabled

TPWMTHRS

Specifies the upper velocity for operation in
StealthChop. Entry the TSTEP reading (time
between two microsteps) when operating at the
desired threshold velocity.

0 …

1048575

StealthChop is disabled if

TSTEP falls TPWMTHRS

PWM_LIM

Limiting value for limiting the current jerk when
switching from SpreadCycle to StealthChop.
Reduce the value to yield a lower current jerk.

0 … 15

Upper four bits of 8 bit
amplitude limit
(Default=12)

pwm_
autoscale

Enable automatic current scaling using current
measurement or use forward controlled velocity
based mode.

0

Forward controlled mode

1

Automatic scaling with
current regulator

pwm_
autograd

Enable automatic tuning of PWM_GRAD_AUTO
0

disable, use PWM_GRAD
from register instead

1

enable

PWM_FREQ

PWM frequency selection. Use the lowest setting
giving good results. The frequency measured at
each of the chopper outputs is half of the
effective chopper frequency f

PWM

.

0

f

PWM

=2/1024 f

CLK

1

f

PWM

=2/683 f

CLK

2

f

PWM

=2/512 f

CLK

3

f

PWM

=2/410 f

CLK

PWM_REG

User defined PWM amplitude (gradient) for
velocity based scaling or regulation loop gradient
when pwm_autoscale=1.

1 … 15

Results in 0.5 to 7.5 steps
for PWM_SCALE_AUTO
regulator per fullstep

PWM_OFS

User defined PWM amplitude (offset) for velocity
based scaling and initialization value for automatic
tuning of PWM_OFFS_AUTO.

0 … 255

PWM_OFS=0 disables
linear current scaling
based on current setting

PWM_GRAD

User defined PWM amplitude (gradient) for
velocity based scaling and initialization value for
automatic tuning of PWM_GRAD_AUTO.

0 … 255

Reset value can be pre­programmed by OTP

FREEWHEEL

Stand still option when motor current setting is
zero (I_HOLD=0). Only available with StealthChop
enabled. The freewheeling option makes the
motor easy movable, while both coil short options
realize a passive brake.

0

Normal operation

1

Freewheeling

2

Coil short via LS drivers

3

Coil short cia HS drivers

PWM_SCALE
_AUTO

Read back of the actual StealthChop voltage PWM
scaling correction as determined by the current
regulator. Should regulate to a value close to 0
during tuning procedure.

-255 …
255

(read only) Scaling value
becomes frozen when
operating in SpreadCycle

PWM_GRAD
_AUTO
PWM_OFS
_AUTO

Allow monitoring of the automatic tuning and
determination of initial values for PWM_OFS and
PWM_GRAD.

0 … 255

(read only)

TOFF

General enable for the motor driver, the actual
value does not influence StealthChop

0

Driver off

1 … 15

Driver enabled

TBL

Comparator blank time. This time needs to safely
cover the switching event and the duration of the
ringing on the sense resistor. Choose a setting of
1 or 2 for typical applications. For higher
capacitive loads, 3 may be required. Lower
settings allow StealthChop to regulate down to
lower coil current values.

0

16 t

CLK

1

24 t

CLK

2

32 t

CLK

3

40 t

CLK

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 45

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7 SpreadCycle Chopper

While StealthChop is a voltage mode PWM controlled chopper, SpreadCycle is a cycle-by-cycle current
control. Therefore, it can react extremely fast to changes in motor velocity or motor load. SpreadCycle
will give better performance in medium to high velocity range for motors and applications which
tend to resonance. The currents through both motor coils are controlled using choppers. The choppers
work independently of each other. In Figure 7.1 the different chopper phases are shown.

R

SENSE

I

COIL

On Phase:
current flows in
direction of target
current

R

SENSE

I

COIL

Fast Decay Phase:
current flows in
opposite direction
of target current

R

SENSE

I

COIL

Slow Decay Phase:
current re-circulation

+V

M

+V

M

+V

M

Figure 7.1 Chopper phases

Although the current could be regulated using only on phases and fast decay phases, insertion of the
slow decay phase is important to reduce electrical losses and current ripple in the motor. The
duration of the slow decay phase is specified in a control parameter and sets an upper limit on the
chopper frequency. The current comparator can measure coil current during phases when the current
flows through the sense resistor, but not during the slow decay phase, so the slow decay phase is
terminated by a timer. The on phase is terminated by the comparator when the current through the
coil reaches the target current. The fast decay phase may be terminated by either the comparator or
another timer.

When the coil current is switched, spikes at the sense resistors occur due to charging and discharging
parasitic capacitances. During this time, typically one or two microseconds, the current cannot be
measured. Blanking is the time when the input to the comparator is masked to block these spikes.

The SpreadCycle chopper mode cycles through four phases: on, slow decay, fast decay, and a second
slow decay.

The chopper frequency is an important parameter for a chopped motor driver. A too low frequency
might generate audible noise. A higher frequency reduces current ripple in the motor, but with a too
high frequency magnetic losses may rise. Also power dissipation in the driver rises with increasing
frequency due to the increased influence of switching slopes causing dynamic dissipation. Therefore, a
compromise needs to be found. Most motors are optimally working in a frequency range of 16 kHz to
30 kHz. The chopper frequency is influenced by a number of parameter settings as well as by the
motor inductivity and supply voltage.

Hint

A chopper frequency in the range of 16 kHz to 30 kHz gives a good result for most motors when
using SpreadCycle. A higher frequency leads to increased switching losses.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 46

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7.1 SpreadCycle Settings

The SpreadCycle (patented) chopper algorithm is a precise and simple to use chopper mode which
automatically determines the optimum length for the fast-decay phase. The SpreadCycle will provide
superior microstepping quality even with default settings. Several parameters are available to
optimize the chopper to the application.

Each chopper cycle is comprised of an on phase, a slow decay phase, a fast decay phase and a
second slow decay phase (see Figure 7.3). The two slow decay phases and the two blank times per
chopper cycle put an upper limit to the chopper frequency. The slow decay phases typically make up
for about 30%-70% of the chopper cycle in standstill and are important for low motor and driver
power dissipation.

Calculation of a starting value for the slow decay time TOFF:

EXAMPLE:

Target Chopper frequency: 25kHz.
Assumption: Two slow decay cycles make up for 50% of overall chopper cycle time






















 

For the TOFF setting this means:

 󰇛



 



 󰇜

With 12 MHz clock this gives a setting of TOFF=3.0, i.e. 3.
With 16 MHz clock this gives a setting of TOFF=4.25, i.e. 4 or 5.

The hysteresis start setting forces the driver to introduce a minimum amount of current ripple into
the motor coils. The current ripple must be higher than the current ripple which is caused by resistive
losses in the motor in order to give best microstepping results. This will allow the chopper to
precisely regulate the current both for rising and for falling target current. The time required to
introduce the current ripple into the motor coil also reduces the chopper frequency. Therefore, a
higher hysteresis setting will lead to a lower chopper frequency. The motor inductance limits the
ability of the chopper to follow a changing motor current. Further the duration of the on phase and
the fast decay must be longer than the blanking time, because the current comparator is disabled
during blanking.

It is easiest to find the best setting by starting from a low hysteresis setting (e.g. HSTRT=0, HEND=0)
and increasing HSTRT, until the motor runs smoothly at low velocity settings. This can best be
checked when measuring the motor current either with a current probe or by probing the sense
resistor voltages (see Figure 7.2). Checking the sine wave shape near zero transition will show a small
ledge between both half waves in case the hysteresis setting is too small. At medium velocities (i.e.
100 to 400 fullsteps per second), a too low hysteresis setting will lead to increased humming and
vibration of the motor.

UART OTP

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 47

www.trinamic.com

Figure 7.2 No ledges in current wave with sufficient hysteresis (magenta: current A, yellow &
blue: sense resistor voltages A and B)

A too high hysteresis setting will lead to reduced chopper frequency and increased chopper noise but
will not yield any benefit for the wave shape.

Quick Start

For a quick start, see the Quick Configuration Guide in chapter 16.
For detail procedure see Application Note AN001 - Parameterization of SpreadCycle

As experiments show, the setting is quite independent of the motor, because higher current motors
typically also have a lower coil resistance. Therefore, choosing a low to medium default value for the
hysteresis (for example, effective hysteresis = 4) normally fits most applications. The setting can be
optimized by experimenting with the motor: A too low setting will result in reduced microstep
accuracy, while a too high setting will lead to more chopper noise and motor power dissipation.
When measuring the sense resistor voltage in motor standstill at a medium coil current with an
oscilloscope, a too low setting shows a fast decay phase not longer than the blanking time. When
the fast decay time becomes slightly longer than the blanking time, the setting is optimum. You can
reduce the off-time setting, if this is hard to reach.

The hysteresis principle could in some cases lead to the chopper frequency becoming too low, e.g.
when the coil resistance is high when compared to the supply voltage. This is avoided by splitting
the hysteresis setting into a start setting (HSTRT+HEND) and an end setting (HEND). An automatic
hysteresis decrementer (HDEC) interpolates between both settings, by decrementing the hysteresis
value stepwise each 16 system clocks. At the beginning of each chopper cycle, the hysteresis begins
with a value which is the sum of the start and the end values (HSTRT+HEND), and decrements during
the cycle, until either the chopper cycle ends or the hysteresis end value (HEND) is reached. This way,
the chopper frequency is stabilized at high amplitudes and low supply voltage situations, if the
frequency gets too low. This avoids the frequency reaching the audible range.

Hint

Highest motor velocities sometimes benefit from setting TOFF to 1 or 2 and a short TBL of 1 or 0.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 48

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t

I

target current

target current - hysteresis start

target current + hysteresis start

on sd fd sd

target current + hysteresis end

target current - hysteresis end

HDEC

Figure 7.3 SpreadCycle chopper scheme showing coil current during a chopper cycle

These parameters control SpreadCycle mode:

Even at HSTRT=0 and HEND=0, the TMC2209 sets a minimum hysteresis via analog circuitry.

EXAMPLE:

A hysteresis of 4 has been chosen. You might decide to not use hysteresis decrement. In this case
set:

HEND=6 (sets an effective end value of 6-3=3)
HSTRT=0 (sets minimum hysteresis, i.e. 1: 3+1=4)

In order to take advantage of the variable hysteresis, we can set most of the value to the HSTRT, i.e.
4, and the remaining 1 to hysteresis end. The resulting configuration register values are as follows:

HEND=0 (sets an effective end value of -3)
HSTRT=6 (sets an effective start value of hysteresis end +7: 7-3=4)

Parameter

Description

Setting

Comment

TOFF

Sets the slow decay time (off time). This setting also
limits the maximum chopper frequency.
For operation with StealthChop, this parameter is not
used, but it is required to enable the motor. In case
of operation with StealthChop only, any setting is
OK.
Setting this parameter to zero completely disables all
driver transistors and the motor can free-wheel.

0

chopper off

1…15

off time setting
N

CLK

= 24 + 32*TOFF
(1 will work with minimum
blank time of 24 clocks)

TBL

Comparator blank time. This time needs to safely
cover the switching event and the duration of the
ringing on the sense resistor. For most
applications, a setting of 1 or 2 is good. For highly
capacitive loads, a setting of 2 or 3 will be
required.

0

16 t

CLK

1

24 t

CLK

2

32 t

CLK

3

40 t

CLK

HSTRT

Hysteresis start setting. This value is an offset from
the hysteresis end value HEND.

0…7

HSTRT=1…8
This value adds to HEND.

HEND

Hysteresis end setting. Sets the hysteresis end value

after a number of decrements. The sum HSTRT+HEND
must be ≤16. At a current setting of max. 30
(amplitude reduced to 240), the sum is not limited.

0…2

-3…-1: negative HEND

3

0: zero HEND

4…15

1…12: positive HEND

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 49

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8 Selecting Sense Resistors

Set the desired maximum motor current by selecting an appropriate value for the sense resistor. The
following table shows the RMS current values which can be reached using standard resistors and
motor types fitting without additional motor current scaling.

CHOICE OF R

SENSE

AND RESULTING MAX. MOTOR CURRENT

R

SENSE

[Ω]

RMS current [A]

VREF=2.5V (or open),
IRUN=31,
vsense=0 (standard)

Fitting motor type

(examples)

1.00

0.23

300mA motor

0.82

0.27

0.75

0.30

0.68

0.33

400mA motor

0.50

0.44

500mA motor

470m

0.47

390m

0.56

600mA motor

330m

0.66

700mA motor

270m

0.79

800mA motor

220m

0.96

1A motor

180m

1.15

1.2A motor

150m

1.35

1.5A motor

120m

1.64

1.7A motor

100m

1.92

2A motor
75m

2.4*)

*) Value exceeds upper current rating, scaling down required, e.g. by reduced VREF.

Sense resistors should be carefully selected. The full motor current flows through the sense resistors.
Due to chopper operation the sense resistors see pulsed current from the MOSFET bridges. Therefore,
a low-inductance type such as film or composition resistors is required to prevent voltage spikes
causing ringing on the sense voltage inputs leading to unstable measurement results. Also, a low­inductance, low-resistance PCB layout is essential. Any common GND path for the two sense resistors
must be avoided, because this would lead to coupling between the two current sense signals. A
massive ground plane is best. Please also refer to layout considerations in chapter 21.

The sense resistor needs to be able to conduct the peak motor coil current in motor standstill
conditions, unless standby power is reduced. Under normal conditions, the sense resistor conducts
less than the coil RMS current, because no current flows through the sense resistor during the slow
decay phases. A 0.5W type is sufficient for most applications up to 1.2A RMS current.

Attention

Be sure to use a symmetrical sense resistor layout and short and straight sense resistor traces of
identical length. Well matching sense resistors ensure best performance.
A compact layout with massive ground plane is best to avoid parasitic resistance effects.
Check the resulting motor current in a practical application and with the desired motor.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 50

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9 Motor Current Control

The basic motor current is set by the resistance of the sense resistors. Several possibilities allow
scaling down motor current, e.g. to adapt for different motors, or to reduce motor current in standstill
or low load situations.

METHODS FOR SCALING MOTOR CURRENT

Method

Parameters

Range

Primary Use

Pin VREF
voltage
(chapter 9.1)

VREF input scales
IRUN and IHOLD.
Can be disabled by
GCONF.i_scale_analog

2.5V: 100% …

0.5V: 20%
>2.5V or open: 100%
<0.5V: not recommended

- Fine tuning of motor current

to fit the motor type

- Manual tuning via poti

- Delayed or soft power-up

- Standstill current reduction

(preferred only with
SpreadCycle)

Pin ENN

Disable / enable
driver stage

0: Motor enable
1: Motor disable

- Disable motor to allow

freewheeling

Pin PDN_UART

Disable / enable
standstill current
reduction to IHOLD

0: Standstill current
reduction enabled.
1: Disable

- Enable current reduction to

reduce heat up in stand still

OTP memory

OTP_IHOLD,
OTP_IHOLDDELAY

9% to 78% standby
current.
Reduction in about
300ms to 2.5s

- Program current reduction to

fit application for highest
efficiency and lowest heat up

OTP memory

otp_internalRsense

0: Use sense resistors
1: Internal resistors

- Save two sense resistors on

BOM, set current by single
inexpensive 0603 resistor.

UART interface

IHOLD_IRUN
TPOWERDOWN
OTP

IRUN, IHOLD:

1/32 to 32/32 of full
scale current.

- Fine programming of run and

hold (stand still) current

- Change IRUN for situation

specific motor current

- Set OTP options

UART interface

CHOPCONF.vsense
flag

0: Normal, most robust
1: Reduced voltage level

- Set vsense for half power

dissipation in sense resistor to
use smaller 0.25W resistors.

Select the sense resistor to deliver enough current for the motor at full current scale (VREF=2.5V). This
is the default current scaling (IRUN = 31).

STANDALONE MODE RMS RUN CURRENT CALCULATION:













 

















IRUN and IHOLD allow for scaling of the actual current scale (CS) from 1/32 to 32/32 when using UART
interface, or via automatic standstill current reduction:

RMS CURRENT CALCULATION WITH UART CONTROL OPTIONS OR HOLD CURRENT SETTING:







  













 









CS is the current scale setting as set by the IHOLD and IRUN.
VFS is the full scale voltage as determined by vsense control bit (please refer to electrical

characteristics, V

SRTL

and V

SRTH

). Default is 325mV.

With analog scaling of VFS (I_scale_analog=1, default), the resulting voltage VFS‘ is calculated by:

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 51

www.trinamic.com





󰆒

 







with V

VREF

the voltage on pin VREF in the range 0V to V

5VOUT

/2

Hint

For best precision of current setting, measure and fine tune the current in the application.

PARAMETERS FOR MOTOR CURRENT CONTROL

Parameter

Description

Setting

Comment

IRUN

Current scale when motor is running. Scales coil
current values as taken from the internal sine
wave table. For high precision motor operation,
work with a current scaling factor in the range 16
to 31, because scaling down the current values
reduces the effective microstep resolution by
making microsteps coarser.

0 … 31

scaling factor
1/32, 2/32, … 32/32

IRUN is full scale (setting

31) in standalone mode.

IHOLD

Identical to IRUN, but for motor in stand still.

IHOLD
DELAY

Allows smooth current reduction from run current
to hold current. IHOLDDELAY controls the number
of clock cycles for motor power down after
TPOWERDOWN in increments of 2^18 clocks:
0=instant power down, 1..15: Current reduction
delay per current step in multiple of 2^18 clocks.

Example: When using IRUN=31 and IHOLD=16, 15
current steps are required for hold current
reduction. A IHOLDDELAY setting of 4 thus results
in a power down time of 4*15*2^18 clock cycles,
i.e. roughly one second at 16MHz clock frequency.

0

instant IHOLD

1 … 15

1*218 … 15*218
clocks per current
decrement

TPOWER
DOWN

Sets the delay time from stand still (stst) detection
to motor current power down. Time range is
about 0 to 5.6 seconds.

0 … 255

0…((2^8)-1) * 2^18 t

CLK

A minimum setting of 2
is required to allow
automatic tuning of

PWM_OFFS_AUTO

vsense

Allows control of the sense resistor voltage range
for full scale current. The low voltage range
allows a reduction of sense resistor power
dissipation.

0

VFS = 0.32 V

1

VFS = 0.18 V

9.1 Analog Current Scaling VREF

When a high flexibility of the output current scaling is desired, the analog input of the driver can be
used for current control, rather than choosing a different set of sense resistors or scaling down the
run current via the interface using IRUN or IHOLD parameters. This way, a simple voltage divider
adapts a board to different motors.

VREF SCALES THE MOTOR CURRENT

The TMC2209 provides an internal reference voltage for current control, directly derived from the
5VOUT supply output. Alternatively, an external reference voltage can be used. This reference voltage
becomes scaled down for the chopper comparators. The chopper comparators compare the voltages
on BRA and BRB to the scaled reference voltage for current regulation. When I_scale_analog in GCONF
is enabled (default), the external voltage on VREF is amplified and filtered and becomes used as
reference voltage. A voltage of 2.5V (or any voltage between 2.5V and 5V) gives the same current

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 52

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scaling as the internal reference voltage. A voltage between 0V and 2.5V linearly scales the current
between 0 and the current scaling defined by the sense resistor setting. It is not advised to work
with reference voltages below about 0.5V to 1V for full scale, because relative analog noise caused by
digital circuitry and power supply ripple has an increased impact on the chopper precision at low
VREF voltages. For best precision, choose the sense resistors in a way that the desired maximum
current is reached with VREF in the range 2V to 2.4V. Be sure to optimize the chopper settings for the
normal run current of the motor.

DRIVING VREF

The easiest way to provide a voltage to VREF is to use a voltage divider from a stable supply voltage
or a microcontroller’s DAC output. A PWM signal also allows current control. The PWM becomes
transformed to an analog voltage using an additional R/C low-pass at the VREF pin. The PWM duty
cycle controls the analog voltage. Choose the R and C values to form a low pass with a corner
frequency of several milliseconds while using PWM frequencies well above 10 kHz. VREF additionally
provides an internal low-pass filter with 3.5kHz bandwidth.

Hint

Using a low reference voltage (e.g. below 1V), for adaptation of a high current driver to a low current
motor will lead to reduced analog performance. Adapt the sense resistors to fit the desired motor
current for the best result.

VREF

8 Bit DAC

Digital
current
control

2.5V
precision
reference

0-2.4V for
current scaling

VREF

PWM output

of µC with

>20kHz

0-2.4V for
current scaling

22k

1µ

Precision current scaler Simple PWM based current scaler

VREF

1-2.4V for fixed
current scaling

R1

Fixed resistor divider to set current scale

(use external reference for enhanced precision)

R2

5VOUT or precise

reference voltage

R1+R2»10K

R3

100k

Optional

digital

control

BC847

Analog ScalingAnalog Scaling Analog Scaling

Figure 9.1 Scaling the motor current using the analog input

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 53

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10 Internal Sense Resistors

The TMC2209 provides the option to eliminate external sense resistors. In this mode the external
sense resistors become omitted (shorted) and the internal on-resistance of the power MOSFETs is
used for current measurement (see chapter 3.2). As MOSFETs are both, temperature dependent and
subject to production stray, a tiny external resistor connected from +5VOUT to VREF provides a precise
absolute current reference. This resistor converts the 5V voltage into a reference current. Be sure to
directly attach BRA and BRB pins to GND in this mode near the IC package. The mode is enabled by
setting internal_Rsense in GCONF (OTP option).

COMPARING INTERNAL SENSE RESISTORS VS. SENSE RESISTORS

Item

Internal Sense Resistors

External Sense Resistors

Ease of use

Need to set OTP parameter
before motor enable

(+) Default
Cost

(+) Save cost for sense resistors

Current precision

Slightly reduced

(+) Good

Current Range
Recommended

200mA RMS to 1.4A RMS

50mA to 2A RMS

Recommended
chopper

StealthChop or SpreadCycle
SpreadCycle shows slightly more
distortion at >1.4A RMS

StealthChop or SpreadCycle

While the RDSon based measurements bring benefits concerning cost and size of the driver, it gives
slightly less precise coil current regulation when compared to external sense resistors. The internal
sense resistors have a certain temperature dependence, which is automatically compensated by the
driver IC. However, for high current motors, a temperature gradient between the ICs internal sense
resistors and the compensation circuit will lead to an initial current overshoot of some 10% during
driver IC heat up. While this phenomenon shows for roughly a second, it might even be beneficial to
enable increased torque during initial motor acceleration.

PRINCIPLE OF OPERATION

A reference current into the VREF pin is used as reference for the motor current. In order to realize a
certain current, a single resistor (R

REF

) can be connected between 5VOUT and VREF (pls. refer the table
for the choice of the resistor). VREF input resistance is about 0.45kOhm. The resulting current into
VREF is amplified 3000 times. Thus, a current of 0.33mA yields a motor current of 1.0A peak, or 0.7A
RMS. For calculation of the reference resistor, the internal resistance of VREF needs to be considered
additionally.

CHOICE OF R

REF

FOR OPERATION WITHOUT SENSE RESISTORS

R

REF

[Ω]

Peak current [A]
(CS=31, vsense=0)

RMS current [A]

(CS=31, vsense=0)

6k2

2.26

1.59

6k8

1.92

1.35

7k5

1.76

1.24

8k2

1.63

1.15

9k1

1.49

1.05

10k

1.36

0.96

12k

1.15

0.81

15k

0.94

0.66

18k

0.79

0.55

22k

0.65

0.45

27k

0.60

0.42

33k

0.54

0.38

UART OTP

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 54

www.trinamic.com

vsense=1 allows a lower peak current setting of about 55% of the value yielded with vsense=0 (as
specified by V

SRTH

/ V

SRTL

).

In RDSon measurement mode, connect the BRA and BRB pins to GND using the shortest possible path
(i.e. shortest possible PCB path). RDSon based measurement gives best results when combined with
StealthChop. When using SpreadCycle with RDSon based current measurement, slightly asymmetric
current measurement for positive currents (on phase) and negative currents (fast decay phase) may
result in chopper noise. This especially occurs at high die temperature and increased motor current.

Note

The absolute current levels achieved with RDSon based current sensing may depend on PCB layout
exactly like with external sense resistors, because trace resistance on BR pins will add to the effective
sense resistance. Therefore, we recommend to measure and calibrate the current setting within the
application.

Thumb rule

RDSon based current sensing works best for motors with up to 1.4A RMS current. The best results are
yielded with StealthChop operation in combination with RDSon based current sensing.
For most precise current control and for best results with SpreadCycle, it is recommended to use
external 1% sense resistors rather than RDSon based current control.

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11 StallGuard4 Load Measurement

StallGuard4 provides an accurate measurement of the load on the motor. It is developed for operation
in conjunction with StealthChop. StallGuard can be used for stall detection as well as other uses at
loads below those which stall the motor, such as CoolStep load-adaptive current reduction. The
StallGuard4 measurement value changes linearly over a wide range of load, velocity, and current
settings, as shown in Figure 11.1. When approaching maximum motor load, the value goes down to a
motor-specific lower value. This corresponds to a load angle of 90° between the magnetic field of the
coils and magnets in the rotor. This also is the most energy-efficient point of operation for the motor.

motor load

(% max. torque)

StallGuard4 reading

SG_RESULT

50

100

150

200

250

300

350

400

450

500

0 10 20 30 40 50 60 70 80 90 100

Start value depends
on motor, velocity
and operating current

Motor stalls above this point.
Load angle exceeds 90° and
available torque sinks.

SG_RESULT reaches compare

value and indicates danger of

stall. This point is set by

stallGuard threshold value

SGTHRS.

Stall detection

threshold SGTHRS*2

100% load value depends on
motor, operating current and
velocity

Stall Output

high

low

Figure 11.1 Function principle of StallGuard4

Parameter

Description

Setting

Comment

SGTHRS

This value controls the StallGuard4 threshold
level for stall detection. It compensates for
motor specific characteristics and controls
sensitivity. A higher value gives a higher
sensitivity. A higher value makes StallGuard4
more sensitive and requires less torque to
indicate a stall.

0… 255

The double of this value is
compared to SG_RESULT.
The stall output becomes
active if SG_RESULT fall
below this value.

Status word

Description

Range

Comment

SG_RESULT

This is the StallGuard4 result. A higher reading
indicates less mechanical load. A lower reading
indicates a higher load and thus a higher load
angle.

0… 510

Low value: highest load
High value: high load

In order to use StallGuard4, check the sensitivity of the motor at border conditions.

11.1 StallGuard4 vs. StallGuard2

StallGuard4 is optimized for operation with StealthChop, its predecessor StallGuard2 works with
SpreadCycle. The function is similar: Both deliver a load value, going from a high value at low load, to
a low value at high load. While StallGuard2 becomes tuned to show a “0”-reading for stall detection,
StallGuard4 uses a comparison-value to trigger stall detection, rather than shifting SG_RESULT itself.

UART

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11.2 Tuning StallGuard4

The StallGuard4 value SG_RESULT is affected by motor-specific characteristics and application-specific
demands on load, coil current, and velocity. Therefore, the easiest way to tune the StallGuard4
threshold SGTHRS for a specific motor type and operating conditions is interactive tuning in the actual
application.

INITIAL PROCEDURE FOR TUNING STALLGUARD SGTHRS

1. Operate the motor at the normal operation velocity for your application and monitor SG_RESULT.

2. Apply slowly increasing mechanical load to the motor. Check the lowest value of SG_RESULT

before the motor stalls. Use this value as starting value for SGTHRS (apply half of the value).

3. Now monitor the StallGuard output signal via DIAG output (configure properly, also set

TCOOLTHRS to match the lower velocity limit for operation) and stop the motor when a pulse is
seen on the respective output. Make sure, that the motor is safely stopped whenever it is stalled.
Increase SGTHRS if the motor becomes stopped before a stall occurs.

4. The optimum setting is reached when a stall is safely detected and leads to a pulse at DIAG in

the moment where the stall occurs. SGTHRS in most cases can be tuned for a certain motion
velocity or a velocity range. Make sure, that the setting works reliable in a certain range (e.g. 80%
to 120% of desired velocity) and also under extreme motor conditions (lowest and highest
applicable temperature).

DIAG is pulsed by StallGuard, when SG_RESULT falls below SGTHRS. It is only enabled in StealthChop
mode, and when TCOOLTHRS ≥ TSTEP > TPWMTHRS
The external motion controller should react to a single pulse by stopping the motor if desired. Set

TCOOLTHRS to match the lower velocity threshold where StallGuard delivers a good result.

SG_RESULT measurement has a high resolution, and there are a few ways to enhance its accuracy, as

described in the following sections.

11.3 StallGuard4 Update Rate

The StallGuard4 measurement value SG_RESULT is updated with each full step of the motor. This is
enough to safely detect a stall, because a stall always means the loss of four full steps.

11.4 Detecting a Motor Stall

To safely detect a motor stall, the stall threshold must be determined using a specific SGTHRS setting
and a specific motor velocity or velocity range. Further, the motor current setting has a certain
influence and should not be modified, once optimum values are determined. Therefore, the maximum
load needs to be determined the motor can drive without stalling. At the same time, monitor
SG_RESULT at this load. The stall threshold should be a value safely within the operating limits, to
allow for parameter stray. More refined evaluation may also react to a change of SG_RESULT rather
than comparing to a fixed threshold. This will rule out certain effects which influence the absolute
value.

11.5 Limits of StallGuard4 Operation

StallGuard4 does not operate reliably at extreme motor velocities: Very low motor velocities (for many
motors, less than one revolution per second) generate a low back EMF and make the measurement
unstable and dependent on environment conditions (temperature, etc.). Other conditions will also lead
to a poor response of the measurement value SG_RESULT to the motor load. Very high motor
velocities, in which the full sinusoidal current is not driven into the motor coils also leads to poor
response. These velocities are typically characterized by the motor back EMF exceeding the supply
voltage.

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12 CoolStep Operation

CoolStep is an automatic smart energy optimization for stepper motors based on the motor
mechanical load, making them “green”.

12.1 User Benefits

CoolStep allows substantial energy savings, especially for motors which see varying loads or operate
at a high duty cycle. Because a stepper motor application needs to work with a torque reserve of 30%
to 50%, even a constant-load application allows significant energy savings because CoolStep
automatically enables torque reserve when required. Reducing power consumption keeps the system
cooler, increases motor life, and allows reducing cost in the power supply and cooling components.

Reducing motor current by half results in reducing power by a factor of four.

12.2 Setting up for CoolStep

CoolStep is controlled by several parameters, but two are critical for understanding how it works:

Parameter

Description

Range

Comment

SEMIN

4-bit unsigned integer that sets a lower threshold.
If SG_RESULT goes below this threshold, CoolStep
increases the current to both coils. The 4-bit
SEMIN value is scaled by 32 to cover the lower
half of the range of the 10-bit SG value. (The
name of this parameter is derived from
SmartEnergy, which is an earlier name for
CoolStep.)

0

disable CoolStep

1…15

threshold is SEMIN*32
Once SGTHRS has been
determined, use
1/16*SGTHRS+1
as a starting point for

SEMIN.

SEMAX

4-bit unsigned integer that controls an upper
threshold. If SG is sampled equal to or above this

threshold enough times, CoolStep decreases the
current to both coils. The upper threshold is
(SEMIN + SEMAX + 1)*32.

0…15

threshold is
(SEMIN+SEMAX+1)*32
0 to 2 recommended

Figure 12.1 shows the operating regions of CoolStep:

- The black line represents the SG_RESULT measurement value.

- The blue line represents the mechanical load applied to the motor.

- The red line represents the current into the motor coils.

When the load increases, SG_RESULT falls below SEMIN, and CoolStep increases the current. When the
load decreases, SG_RESULT rises above (SEMIN + SEMAX + 1) * 32, and the current is reduced.

Energy efficiency

–

consumption decreased up to 75%

Motor generates less heat

–

improved mechanical precision

Less cooling infrastructure

–

for motor and driver

Cheaper motor

–

does the job!

UART

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stallGuard2

reading

0=maximum load

motor current increment area

motor current reduction area

stall possible

SEMIN

SEMAX+SEMIN+1

Zeit

motor current

current setting I_RUN
(upper limit)

½ or ¼ I_RUN
(lower limit)

mechanical load

current increment due to

increased load

slow current reduction due

to reduced motor load

load angle optimized load angle optimized

load

angle

optimized

Figure 12.1 CoolStep adapts motor current to the load

Five more parameters control CoolStep and one status value is returned:

Parameter

Description

Range

Comment

SEUP

Sets the current increment step. The current
becomes incremented for each measured
StallGuard value below the lower threshold.

0…3

step width is
1, 2, 4, 8

SEDN

Sets the number of StallGuard readings above the
upper threshold necessary for each current
decrement of the motor current.

0…3

number of StallGuard
measurements per
decrement:
32, 8, 2, 1

SEIMIN

Sets the lower motor current limit for CoolStep
operation by scaling the IRUN current setting.
Operate well above the minimum motor current
as determined for StealthChop current regulation.

0

0: 1/2 of IRUN
Attention: use IRUN≥10

1

1: 1/4 of IRUN

Attention: use IRUN≥20

TCOOLTHRS

Lower velocity threshold for switching on
CoolStep and stall output. Below this velocity
CoolStep becomes disabled (not used in STEP/DIR
mode). Adapt to the lower limit of the velocity
range where StallGuard gives a stable result.

1…
2^20-1

Specifies lower CoolStep
velocity by comparing
the threshold value to

TSTEP

TPWMTHRS

Upper velocity threshold value for CoolStep and
stop on stall. Above this velocity the driver
switches to SpreadCycle. This also disables
CoolStep and StallGuard.

1…
2^20-1

This setting typically is
used during chopper
mode configuration,
only.

Status
word

Description

Range

Comment

CSACTUAL

This status value provides the actual motor
current scale as controlled by CoolStep. The value

goes up to the IRUN value and down to the
portion of IRUN as specified by SEIMIN.

0…31

1/32, 2/32, … 32/32

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12.3 Tuning CoolStep

CoolStep uses SG_RESULT to operate the motor near the optimum load angle of +90°. The basic
setting to be tuned is SEMIN. Set SEMIN to a value which safely activates CoolStep current increment
before the motor stalls. In case SGTHRS has been tuned before, a lower starting value is

SEMIN = 1+SGTHRS/16.

The current increment speed is specified in SEUP, and the current decrement speed is specified in
SEDN. They can be tuned separately because they are triggered by different events that may need
different responses. The encodings for these parameters allow the coil currents to be increased much
more quickly than decreased, because crossing the lower threshold is a more serious event that may
require a faster response. If the response is too slow, the motor may stall. In contrast, a slow
response to crossing the upper threshold does not risk anything more serious than missing an
opportunity to save power.

CoolStep operates between limits controlled by the current scale parameter IRUN and the seimin bit.

Attention

When CoolStep increases motor current, spurious detection of motor stall may occur. For best results,
disable CoolStep during StallGuard based homing.
In case StallGuard is desired in combination with CoolStep, try increasing coolStep lower threshold
SEMIN as required.

12.3.1 Response Time

For fast response to increasing motor load, use a high current increment step SEUP. If the motor load
changes slowly, a lower current increment step can be used to avoid motor oscillations.

Hint
The most common and most beneficial use is to adapt CoolStep for operation at the typical system
target operation velocity and to set the velocity thresholds according. As acceleration and
decelerations normally shall be quick, they will require the full motor current, while they have only a
small contribution to overall power consumption due to their short duration.

12.3.2 Low Velocity and Standby Operation

Because CoolStep is not able to measure the motor load in standstill and at very low RPM, a lower
velocity threshold is provided for enabling CoolStep. It should be set to an application specific default
value. Below this threshold the normal current setting via IRUN respectively IHOLD is valid.

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13 STEP/DIR Interface

The STEP and DIR inputs provide a simple, standard interface compatible with many existing motion
controllers. The MicroPlyer step pulse interpolator brings the smooth motor operation of high­resolution microstepping to applications originally designed for coarser stepping.

13.1 Timing

Figure 13.1 shows the timing parameters for the STEP and DIR signals, and the table below gives
their specifications. Only rising edges are active. STEP and DIR are sampled and synchronized to the
system clock. An internal analog filter removes glitches on the signals, such as those caused by long
PCB traces. If the signal source is far from the chip, and especially if the signals are carried on cables,
the signals should be filtered or differentially transmitted.

+VCC_IO

SchmittTrigger

0.44 VCC_IO

0.56 VCC_IO

83k

C

Input filter

R*C = 20ns +-30%

STEP

or DIR

Input

Internal
Signal

DIR

STEP

t

DSH

t

SH

t

SL

t

DSU

Active edge

(DEDGE=0)

Active edge

(DEDGE=0)

Figure 13.1 STEP and DIR timing, Input pin filter

STEP and DIR interface timing

AC-Characteristics

clock period is t

CLK

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

step frequency (at maximum
microstep resolution)

f

STEP

½ f

CLK

fullstep frequency

fFS f

CLK

/512

STEP input minimum low time

tSL

max(t

FILTSD

,

t

CLK

+20)

100

ns

STEP input minimum high time

t

SH

max(t

FILTSD

,

t

CLK

+20)

100

ns

DIR to STEP setup time

t

DSU

20

ns

DIR after STEP hold time

t

DSH

20

ns

STEP and DIR spike filtering time
*)

t

FILTSD

rising and falling
edge

13

20

30

ns

STEP and DIR sampling relative
to rising CLK input

t

SDCLKHI

before rising edge
of CLK input

t

FILTSD

ns

*) These values are valid with full input logic level swing, only. Asymmetric logic levels will increase
filtering delay t

FILTSD

, due to an internal input RC filter.

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13.2 Changing Resolution

The TMC2209 includes an internal microstep table with 1024 sine wave entries to generate sinusoidal
motor coil currents. These 1024 entries correspond to one electrical revolution or four fullsteps. The
microstep resolution setting determines the step width taken within the table. Depending on the DIR
input, the microstep counter is increased (DIR=0) or decreased (DIR=1) with each STEP pulse by the
step width. The microstep resolution determines the increment respectively the decrement. At
maximum resolution, the sequencer advances one step for each step pulse. At half resolution, it
advances two steps. Increment is up to 256 steps for fullstepping. The sequencer has special
provision to allow seamless switching between different microstep rates at any time. When switching
to a lower microstep resolution, it calculates the nearest step within the target resolution and reads
the current vector at that position. This behavior especially is important for low resolutions like
fullstep and halfstep, because any failure in the step sequence would lead to asymmetrical run when
comparing a motor running clockwise and counterclockwise.

EXAMPLES:

Fullstep: Cycles through table positions: 128, 384, 640 and 896 (45°, 135°, 225° and 315° electrical

position, both coils on at identical current). The coil current in each position
corresponds to the RMS-Value (0.71 * amplitude). Step size is 256 (90° electrical)

Half step: The first table position is 64 (22.5° electrical), Step size is 128 (45° steps)
Quarter step: The first table position is 32 (90°/8=11.25° electrical), Step size is 64 (22.5° steps)

This way equidistant steps result and they are identical in both rotation directions. Some older drivers
also use zero current (table entry 0, 0°) as well as full current (90°) within the step tables. This kind of
stepping is avoided because it provides less torque and has a worse power dissipation in driver and
motor.

Step position

table position

current coil A

current coil B

Half step 0

64

38.3%

92.4%

Full step 0

128

70.7%

70.7%

Half step 1

192

92.4%

38.3%

Half step 2

320

92.4%

-38.3%

Full step 1

384

70.7%

-70.7%

Half step 3

448

38.3%

-92.4%

Half step 4

576

-38.3%

-92.4%

Full step 2

640

-70.7%

-70.7%

Half step 5

704

-92.4%

-38.3%

Half step 6

832

-92.4%

38.3%

Full step 3

896

-70.7%

70.7%

Half step 7

960

-38.3%

92.4%

See chapter 3.4 for resolution settings available in stand-alone mode.

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13.3 MicroPlyer Step Interpolator and Stand Still Detection

For each active edge on STEP, MicroPlyer produces microsteps at 256x resolution, as shown in Figure

13.2. It interpolates the time in between of two step impulses at the step input based on the last
step interval. This way, from 2 microsteps (128 microstep to 256 microstep interpolation) up to 256
microsteps (full step input to 256 microsteps) are driven for a single step pulse.

The step rate for the interpolated 2 to 256 microsteps is determined by measuring the time interval of
the previous step period and dividing it into up to 256 equal parts. The maximum time between two
microsteps corresponds to 220 (roughly one million system clock cycles), for an even distribution of
256 microsteps. At 12 MHz system clock frequency, this results in a minimum step input frequency of
roughly 12 Hz for MicroPlyer operation. A lower step rate causes a standstill event to be detected. At
that frequency, microsteps occur at a rate of (system clock frequency)/216 ~ 256 Hz. When a stand still
is detected, the driver automatically begins standby current reduction if selected by pin PDN.

Attention

MicroPlyer only works perfectly with a jitter-free STEP frequency.

STEP

Interpolated

microstep

Active edge

(dedge=0)

Active edge

(dedge=0)

Active edge

(dedge=0)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 32

Active edge

(dedge=0)

STANDSTILL
(stst) active

33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Motor

angle

52 53 54 55 56 57 58 59 60 61 62 63 64 65 6651

2^20 t

CLK

Figure 13.2 MicroPlyer microstep interpolation with rising STEP frequency (Example: 16 to 256)

In Figure 13.2, the first STEP cycle is long enough to set the stst bit standstill. Detection of standstill
will enable the standby current reduction. This bit is cleared on the next STEP active edge. Then, the
external STEP frequency increases. After one cycle at the higher rate MicroPlyer adapts the interpolated
microstep rate to the higher frequency. During the last cycle at the slower rate, MicroPlyer did not
generate all 16 microsteps, so there is a small jump in motor angle between the first and second
cycles at the higher rate.

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13.4 Index Output

An active INDEX output signals that the sine curve of motor coil A is at its positive zero transition.
This correlates to the zero point of the microstep sequence. Usually, the cosine curve of coil B is at its
maximum at the same time. Thus, the index signal is active once within each electrical period, and
corresponds to a defined position of the motor within a sequence of four fullsteps. The INDEX output
this way allows the detection of a certain microstep pattern, and thus helps to detect a position with
more precision than a stop switch can do.

COIL A

COIL B

Current

Time

Time

Time

Current

INDEX

STEPS

0

Figure 13.3 Index signal at positive zero transition of the coil A sine curve

Hint

The index output allows precise detection of the microstep position within one electrical wave, i.e.
within a range of four fullsteps. With this, homing accuracy and reproducibility can be enhanced to
microstep accuracy, even when using an inexpensive home switch.

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14 Internal Step Pulse Generator

The TMC2209 family integrates a high-resolution step pulse generator, allowing motor motion via the
UART interface. However, no velocity ramping is provided. Ramping is not required, if the target
motion velocity is smaller than the start & stop frequency of the motor. For higher velocities, ramp up
the frequency in small steps to accelerate the motor, and ramp down again to decelerate the motor.
Figure 14.1 shows an example motion profile ramping up the motion velocity in discrete steps.
Choose the ramp velocity steps considerably smaller than the maximum start velocity of the motor,
because motor torque drops at higher velocity, and motor load at higher velocity typically increases.

v

t

acceleration deceleration

motor

stop

Stop velocity

Start velocity

0

Target Velocity

Theoretical profile

VACTUAL

constant velocity

Figure 14.1 Software generated motion profile

PARAMETER VS. UNITS

Parameter / Symbol

Unit

calculation / description / comment

f

CLK

[Hz]

[Hz]

clock frequency of the TMC2209 in [Hz]

µstep velocity v[Hz]

µsteps / s

v[Hz] = VACTUAL[2209] * ( f

CLK

[Hz]/2 / 2^23 )
With internal oscillator:
v[Hz] = VACTUAL[2209] * 0.715Hz

USC microstep count

counts

microstep resolution in number of microsteps
(i.e. the number of microsteps between two
fullsteps – normally 256)

rotations per second v[rps]

rotations / s

v[rps] = v[Hz] / USC / FSC
FSC: motor fullsteps per rotation, e.g. 200

TSTEP, TPWMTHRS

-

TSTEP = f

CLK

/ f

STEP

The time reference for velocity threshold is
referred to the actual microstep frequency of
the step input respectively velocity v[Hz].

VACTUAL

Two’s complement

signed internal
velocity

VACTUAL[2209] = ( f

CLK

[Hz]/2 / 2^23 ) / v[Hz]

With internal oscillator:

VACTUAL[2209] = 0.715Hz / v[Hz]

Hint

To monitor internal step pulse execution, program the INDEX output to provide step pulses
(GCONF.index_step). It toggles upon each step. Use a timer input on your CPU to count pulses.
Alternatively, regularly poll MSCNT to grasp steps done in the previous polling interval. It wraps
around from 1023 to 0.

UART

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15 Driver Diagnostic Flags

The TMC2209 drivers supply a complete set of diagnostic and protection capabilities, like short to GND
protection, short to VS protection and undervoltage detection. A detection of an open load condition
allows testing if a motor coil connection is interrupted. See the DRV_STATUS table for details.

15.1 Temperature Measurement

The driver integrates a four-level temperature sensor (pre-warning and thermal shutdown) for
diagnostics and for protection of the IC against excess heat. The thresholds can be adapted by UART
or OTP programming. Heat is mainly generated by the motor driver stages, and, at increased voltage,
by the internal voltage regulator. Most critical situations, where the driver MOSFETs could be
overheated, are avoided by the short to GND protection. For many applications, the overtemperature
pre-warning will indicate an abnormal operation situation and can be used to initiate user warning or
power reduction measures like motor current reduction. The thermal shutdown is just an emergency
measure and temperature rising to the shutdown level should be prevented by design.

TEMPERATURE THRESHOLDS

Overtemperature
Setting

Comment

143°C
(OTPW: 120°C)

Default setting. This setting is safest to switch off the driver stage before the IC
can be destroyed by overheating. On a large PCB, the power MOSFETs reach
roughly 150°C peak temperature when the temperature detector is triggered with
this setting. This is a trip typical point for overtemperature shut down. The
overtemperature pre-warning threshold of 120°C gives lots of headroom to react
to high driver temperature, e.g. by reducing motor current.

150°C
(OTPW:
120°C or 143°C)

Optional setting (OTP or UART). For small PCBs with high thermal resistance
between PCB and environment, this setting provides some additional headroom.
The small PCB shows less temperature difference between the MOSFETs and the
sensor.

157°C
(OTPW: 143°C)

Optional setting (UART). For applications, where a stop of the motor cannot be
tolerated, this setting provides highest headroom, e.g. at high environment
temperature ratings. Using the 143°C overtemperature pre-warning to reduce
motor current ensures that the motor is not switched off by the thermal
threshold.

Attention

Overtemperature protection cannot in all cases avoid thermal destruction of the IC. In case the rated
motor current is exceed, e.g. by operating a motor in StealthChop with wrong parameters, or with
automatic tuning parameters not fitting the operating conditions, excess heat generation can quickly
heat up the driver before the overtemperature sensor can react. This is due to a delay in heat
conduction over the IC die.

After triggering the overtemperature sensor (ot flag), the driver remains switched off until the system
temperature falls below the pre-warning level (otpw) to avoid continuous heating to the shutdown
level.

15.2 Short Protection

The TMC2209 power stages are protected against a short circuit condition by an additional measure­ment of the current flowing through each of the power stage MOSFETs. This is important, as most
short circuit conditions result from a motor cable insulation defect, e.g. when touching the conducting
parts connected to the system ground. The short detection is protected against spurious triggering,
e.g. by ESD discharges, by retrying three times before switching off the motor.

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Once a short condition is safely detected, the corresponding driver bridge (A or B) becomes switched
off, and the s2ga or s2gb flag, respectively s2vsa or s2vsb becomes set. In order to restart the motor,
disable and re-enable the driver. Note, that short protection cannot protect the system and the power
stages for all possible short events, as a short event is rather undefined and a complex network of
external components may be involved. Therefore, short circuits should basically be avoided.

15.3 Open Load Diagnostics

Interrupted cables are a common cause for systems failing, e.g. when connectors are not firmly
plugged. The TMC2209 detects open load conditions by checking, if it can reach the desired motor coil
current. This way, also undervoltage conditions, high motor velocity settings or short and
overtemperature conditions may cause triggering of the open load flag, and inform the user, that
motor torque may suffer. In motor stand still, open load cannot always be measured, as the coils
might eventually have zero current.

Open load detection is provided for system debugging.
In order to safely detect an interrupted coil connection, read out the open load flags at low or
nominal motor velocity operation, only. If possible, use SpreadCycle for testing, as it provides the
most accurate test. However, the ola and olb flags have just informative character and do not cause
any action of the driver.

15.4 Diagnostic Output

The diagnostic output DIAG and the index output INDEX provide important status information. An
active DIAG output shows that the driver cannot work normally, or that a motor stall is detected,
when StallGuard is enabled. The INDEX output signals the microstep counter zero position, to allow
referencing (homing) a drive to a certain current pattern. The function set of the INDEX output can be
modified by UART. Figure 15.1 shows the available signals and control bits.

INDEX

DIAG

Power-on reset

Toggle upon each step

Charge pump undervoltage (uv_cp)

Short circuit (s2vs, s2g) over temperature (ot)

S

R

Q

drv_err

Power stage disable (e.g. pin ENN)

Index pulse

GCONF.index_otpw

GCONF.index_step

MUX

Overtemperature prewarning (otpw)

Overtemperature (ot)

StallDetection
(gated by TPWMTHRS<=TSTEP<=VCOOLTHRS)

Figure 15.1 DIAG and INDEX outputs

UART

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 67

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16 Quick Configuration Guide

This guide is meant as a practical tool to come to a first configuration. Do a minimum set of
measurements and decisions for tuning the driver to determine UART settings or OTP parameters. The
flow-charts concentrate on the basic function set to make a motor run smoothly. Once the motor
runs, you may decide to explore additional features, e.g. freewheeling in more detail. A current probe
on one motor coil is a good aid to find the best settings, but it is not a must.

Current Setting

Sense Resistors

used?

GCONF

set internal_Rsense

Store to OTP 0.6

recommended

N

Analog Scaling?

Y

GCONF

set I_scale_analog

(this is default)

Set VREF as desired

Y

CHOPCONF

set vsense for max.

180mV at sense resistor

(0R15: 1.1A peak)

Set I_RUN as desired up

to 31, I_HOLD 70% of

I_RUN or lower

N

Low Current range?

N

Y

GCONF

clear en_spreadCycle

(default)

Set I_HOLD_DELAY to 1

to 15 for smooth

standstill current decay

Set TPOWERDOWN up

to 255 for delayed

standstill current

reduction

Configure Chopper to

test current settings

stealthChop

Configuration

PWMCONF

set pwm_autoscale,

set pwm_autograd

PWMCONF

select PWM_FREQ with

regard to fCLK for 20-

40kHz PWM frequency

Check hardware
setup and motor

RMS current

CHOPCONF

Enable chopper using basic

config., e.g.: TOFF=5, TBL=2,

HSTART=4, HEND=0

Move the motor by

slowly accelerating

from 0 to VMAX

operation velocity

Is performance

good up to VMAX?

Select a velocity

threshold for switching

to spreadCycle chopper

and set TPWMTHRS

N

SC2

Y

Execute

automatic

tuning

procedure AT

Figure 16.1 Current Setting and first steps with StealthChop

Hint
Use the evaluation board to explore settings and to generate the required configuration datagrams.

UART OTP

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 68

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SC2

Try motion above

TPWMTRHRS, if

used

Coil current

overshoot upon

deceleration?

PWMCONF

decrease PWM_LIM (do

not go below about 5)

Y

Optimize spreadCycle

configuration if TPWMTHRS

used

N

Go to motor stand

still and check

motor current at

IHOLD=IRUN

Stand still current

too high?

N

CHOPCONF, PWMCONF

decrease TBL or PWM

frequency and check

impact on motor motion

Y

GCONF

set en_spreadCycle

spreadCycle

Configuration

CHOPCONF

Enable chopper using basic

config.: TOFF=5, TBL=2,

HSTART=0, HEND=0

Move the motor by
slowly accelerating

from 0 to VMAX

operation velocity

Monitor sine wave motor

coil currents with current

probe at low velocity

CHOPCONF

increase HEND (max. 15)

Current zero

crossing smooth?

N

Move motor very slowly or

try at stand still

CHOPCONF

decrease TOFF (min. 2),

try lower / higher TBL or

reduce motor current

Audible Chopper

noise?

Y

Y

Move motor at medium

velocity or up to max.

velocity

N

Audible Chopper

noise?

CHOPCONF

decrease HEND and

increase HSTART (max.

7)

Y

Finished

Figure 16.2 Tuning StealthChop and SpreadCycle

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 69

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Enable CoolStep

Move the motor at

desired operation

velocity

Does SG_RE SULT change

significantly with chang ed

load?

Monitor SG_RESULT value

and check response with

mechanical load

Is coil

PWM_SCALE_SUM

<255 at VMAX?

Decrease velocity

(upper limit for

CoolStep)

N

Y

Increase velocity

(lower limit for

CoolStep)

N

COOLCONF

Enable coolStep basic config.: Set

SEMIN=1+1/16 SG_RE SULT

Y

Set TCOO LTHRS

slightly above TSTEP at

the selected velocity for

lower velocity limit

Monitor CS_ACTUAL during

motion in velocity range

and check response with

mechanical load

Does CS_ ACTUAL reach

IRUN with load before

motor stall?

Increase SEMIN or

choose narrower

velocity limits

N

C2

C2

Monitor CS_ACTUAL and

motor torque during rapid

mechanical load increment

within application limits

Does CS_ ACTUAL reach

IRUN with load before

motor stall?

Increase SEUPN

Y

Finished

Y

Set SGTHRS

to ½ of the minimum

value seen at

SG_RESULT before stall.

Figure 16.3 Configuration for CoolStep in StealthChop mode

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 70

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OTP programming

Determine stand still current

settings (IHOLD, IHOLDDELAY) and

sense resistor type (internal_Rsense)

Find nearest value fitting for

PWM_GRAD initialization from

table OTP_PWM_GRAD

Determine chopper settings

(CHOPCONF and PWMCONF)

spreadCycle only

mode?

Go for

otp_en_spreadCycle=1

Y

N

Mix spreadCylce

and stealthChop?

Find nearest value fitting

for TPWMTHRS from

table OTP_TPWMTHRS

Y

N

Note all OTP bits to be set

to 1.

Are all OTP bits

programmed?

N

Y

Choose a bit to be programmed and write

OTP byte and bit address to OTP_PROG

including magic code 0xbd

Finished

Wait for 10ms or longer

All bits set in

OTP_READ?

Y

Re-Program missing bits
using 100ms delay time

N

Figure 16.4 OTP programming

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 71

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17 External Reset

The chip is loaded with default values during power on via its internal power-on reset. Some of the
registers are initialized from the OTP at power up. In order to reset the chip to power on defaults,
any of the supply voltages monitored by internal reset circuitry (VS, +5VOUT or VCC_IO) must be
cycled. As +5VOUT is the output of the internal voltage regulator, it cannot be cycled via an external
source except by cycling VS. It is easiest and safest to cycle VCC_IO in order to completely reset the
chip. Also, current consumed from VCC_IO is low and therefore it has simple driving requirements.
Due to the input protection diodes not allowing the digital inputs to rise above VCC_IO level, all
inputs must be driven low during this reset operation. When this is not possible, an input protection
resistor may be used to limit current flowing into the related inputs.

18 Clock Oscillator and Input

The clock is the timing reference for all functions: the chopper frequency, the blank time, the standstill
power down timing, and the internal step pulse generator etc. The on-chip clock oscillator is
calibrated in order to provide timing precise enough for most operation cases.

USING THE INTERNAL CLOCK

Directly tie the CLK input to GND near to the IC if the internal clock oscillator is to be used. The
internal clock frequency is factory-trimmed to 12MHz by OTP programming.

USING AN EXTERNAL CLOCK

When an external clock is available, any frequency of 8 to 13.4MHz (max. 16MHz) can be used to clock
the TMC2209. The duty cycle of the clock signal has to be near 50%, especially for high frequencies.
Ensure minimum high or low input time for the pin (refer to electrical characteristics). Make sure, that
the clock source supplies clean CMOS output logic levels and steep slopes when using a high clock
frequency. The external clock input is enabled with the first positive polarity seen on the CLK input.
Modifying the clock frequency is an easy way to adapt the StealthChop chopper frequency or to
synchronize multiple drivers. Working with a very low clock frequency down to 4 MHz can help
reducing power consumption and electromagnetic emissions, but it will sacrifice some performance.

Use an external clock source to synchronize multiple drivers, or to get precise motor operation with
the internal pulse generator for motion. The external clock frequency selection also allows modifying
the power down timing and the chopper frequency.

Hint
Switching off the external clock frequency would stop the chopper and could lead to an overcurrent
condition. Therefore, TMC2209 has an internal timeout of 32 internal clocks. In case the external clock
fails, it switches back to internal clock.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 72

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19 Absolute Maximum Ratings

The maximum ratings may not be exceeded under any circumstances. Operating the circuit at or near
more than one maximum rating at a time for extended periods shall be avoided by application
design.

Parameter

Symbol

Min

Max

Unit

Supply voltage operating with inductive load

V

VS

-0.5

32

V

Supply and bridge voltage max. *)

V

VMAX

33

V

I/O supply voltage

V

VIO

-0.5

5.5

V

digital supply voltage (when using external supply)

V

5VOUT

-0.5

5.5

V

Logic input voltage

VI

-0.5

V

VIO

+0.5

V

VREF input voltage (Do not exceed both, VCC_IO and
5VOUT by more than 10%, as this enables a test mode)

V

VREF

-0.5 6 V

Maximum current to / from digital pins
and analog low voltage I/Os

IIO +/-10

mA

5V regulator output current (internal plus external load)

I

5VOUT

25

mA

5V regulator continuous power dissipation (VVM-5V) * I

5VOUT

P

5VOUT

0.5

W

Power bridge repetitive output current

IOx 3

A

Junction temperature

TJ

-50

150

°C

Storage temperature

T

STG

-55

150

°C

ESD-Protection for interface pins in application (Human
body model, HBM)

V

ESDAP

4

kV

ESD-Protection for handling (Human body model, HBM)

V

ESD

1

kV

*) Stray inductivity of GND and VS connections will lead to ringing of the supply voltage when driving
an inductive load. This ringing results from the fast switching slopes of the driver outputs in
combination with reverse recovery of the body diodes of the output driver MOSFETs. Even small trace
inductivities as well as stray inductivity of sense resistors can easily generate a few volts of ringing
leading to temporary voltage overshoot. This should be considered when working near the maximum
voltage.

20 Electrical Characteristics

20.1 Operational Range

Parameter

Symbol

Min

Max

Unit

Junction temperature

TJ

-40

125

°C

Supply voltage (using internal +5V regulator)

VVS

5.5

29

V

Supply voltage (using internal +5V regulator) for OTP
programming

VVS

6

29

V

Supply voltage (internal +5V regulator bridged: V

5VOUT=VVS

)

VVS

4.7

5.4

V

I/O supply voltage

V

VIO

3.00

5.25

V

I/O supply voltage during standby

V

VIO

1.50

5.25

V

VCC voltage when using optional external source (supplies
digital logic and charge pump)

V

VCC

4.6

5.25

V

RMS motor coil current per coil (value for design guideline)

I

RMS

1.4

A

RMS motor coil current per coil with duty cycle limit, e.g. 1s
on, 1s standby (value for design guideline)

I

RMS

2.0

A

Peak output current per motor coil output (sine wave peak)
using external or internal current sensing

IOx 2.8

A

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 73

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20.2 DC and Timing Characteristics

DC characteristics contain the spread of values guaranteed within the specified supply voltage range
unless otherwise specified. Typical values represent the average value of all parts measured at +25°C.
Temperature variation also causes stray to some values. A device with typical values will not leave
Min/Max range within the full temperature range.

Power supply current

DC-Characteristics

VVS = V

VSA

= 24.0V

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Total supply current, standby

IS

ENN=0V, VREF=0V

160

300

µA

Total supply current, driver
disabled IVS

IS

f

CLK

=12MHz

7 10

mA

Total supply current, operating,
IVS

IS

f

CLK

=12MHz, 35kHz

chopper, no load

7.5 mA

Supply current, driver disabled,
dependency on CLK frequency

IVS

f

CLK

variable,

additional to I

VS0

0.3

mA/MHz

Internal current consumption
from 5V supply on VCC pin

I

VCC

f

CLK

=12MHz, 35kHz

chopper

4.5 mA

IO supply current (typ. at 3.3V)

I

VIO

no load on outputs,
inputs at VIO or GND
Excludes pull-down
resistors

15

30

µA

Motor driver section

DC- and Timing-Characteristics
VVS = 24.0V

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

RDSON lowside MOSFET

R

ONL

measure at 200mA,
25°C, static state

0.170

0.21

Ω

RDSON highside MOSFET

R

ONH

measure at 200mA,
25°C, static state

0.170

0.21

Ω

slope, MOSFET turning on

t

SLPON

measured at 700mA
load current
(resistive load)

35

60

150

ns

slope, MOSFET turning off

t

SLPOFF

measured at 700mA
load current
(resistive load)

35

60

150

ns

Current sourcing, driver off

I

OIDLE

OXX pulled to GND

120

180

250

µA

Charge pump

DC-Characteristics

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Charge pump output voltage

V

VCP-VVS

operating, typical
f

chop

<40kHz

4.0

V

VCC

-

0.22

V

VCC

V

Charge pump voltage threshold
for undervoltage detection

V

VCP-VVS

using internal 5V
regulator voltage

3.3

3.6

4.0

V

Charge pump frequency

fCP

1/16

f

CLKOSC

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 74

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Linear regulator

DC-Characteristics

VVS = V

VSA

= 24.0V

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Output voltage

V

5VOUT

I

5VOUT

= 0mA

TJ = 25°C

4.80

5.0

5.25

V

Output resistance

R

5VOUT

Static load

1



Deviation of output voltage over
the full temperature range

V

5VOUT(DEV)

I

5VOUT

= 5mA

TJ = full range

+/-30

+/-100

mV

Deviation of output voltage over
the full supply voltage range

V

5VOUT(DEV)

I

5VOUT

= 5mA

VVS = variable

+/-15

+/-30

mV /

10V

Clock oscillator and input

Timing-Characteristics

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Clock oscillator frequency
(factory calibrated)
f

CLKOSC

tJ=-50°C

11.7

MHz

f

CLKOSC

tJ= 25°C

11.5

12.0

12.5

MHz

f

CLKOSC

tJ=150°C

12.1

MHz

External clock frequency
(operating)

f

CLK

Typ. at 40%/60%
dutycycle, Max at
50% dutycycle

4

10-13.4

16

MHz
External clock high / low level
time

t

CLKH

/

t

CLKL

CLK driven to

0.1 V

VIO

/ 0.9 V

VIO

16

ns

External clock first pulse to
trigger switching to external CLK

t

CLKH

/

t

CLKL

CLK driven high

30

25 ns

External clock timeout detection
in cycles of internal f

CLKOSC

x

timeout

External clock stuck
at low or high

32 48

cycles

f

CLKOSC

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 75

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Detector levels

DC-Characteristics

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

VVS undervoltage threshold for
RESET

V

UV_VS

VVS rising

3.5

4.2

4.6

V

V

5VOUT

undervoltage threshold for

RESET

V

UV_5VOUT

V

5VOUT

rising

3.5 V

V

VCC_IO

undervoltage threshold for

RESET

V

UV_VIO

V

VCC_IO

rising (delay

typ. 10µs)

2.1

2.55

3.0

V

V

VCC_IO

undervoltage detector

hysteresis

V

UV_VIOHYST

0.3 V

Short to GND detector threshold
(VVS - VOx)

V

OS2G

2

2.5 3 V

Short to VS detector threshold
(VOx)

V

OS2VS

1.6 2 2.3

V

Short detector delay
(high side / low side switch on
to short detected)

t

S2G

High side output
clamped to VSP-3V

0.8

1.3 2 µs
Overtemperature prewarning
120°C

t

OTPW

Temperature rising

100

120

140

°C

Overtemperature shutdown or
prewarning 143°C (appr. 153°C IC
peak temp.)

t

OT143

Temperature rising

128

143

163

°C
Overtemperature shutdown
150°C (appr. 160°C IC peak temp.)

t

OT150

Temperature rising

135

150

170

°C

Overtemperature shutdown
157°C (appr. 167°C IC peak temp.)

t

OT157

Temperature rising

142

157

177

°C

Difference between temperature
detector and power stage
temperature, slow heat up

t

OTDIFF

Power stage causing
high temperature,
normal 4 Layer PCB

10 °C

Sense resistor voltage levels

DC-Characteristics
f

CLK

=16MHz

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Sense input peak threshold
voltage (low sensitivity)

V

SRTL

vsense=0
csactual=31
CUR_A/B=248

Hyst.=0; I

BRxy

=0

325 mV

Sense input peak threshold
voltage (high sensitivity)

V

SRTH

vsense=1
csactual=31
CUR_A/B=248

Hyst.=0; I

BRxy

=0

180 mV
Sense input tolerance / motor
current full scale tolerance

-using internal reference

I

COIL

I_scale_analog=0,
vsense=0

-5 +5

%

Sense input tolerance / motor
current full scale tolerance

-using external reference voltage

I

COIL

I_scale_analog=1,
V

AIN

=2V, vsense=0

-2 +2

%

Internal resistance from pin BRxy
to internal sense comparator
(additional to sense resistor)

R

BRxy

20 mΩ

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 76

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Digital pins

DC-Characteristics

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Input voltage low level

V

INLO

-0.3

0.3 V

VIO

V

Input voltage high level

V

INHI

0.7 V

VIO

V

VIO

+0.3

V

Input Schmitt trigger hysteresis

V

INHYST

0.12
V

VIO

V

Output voltage low level

V

OUTLO

I

OUTLO

= 2mA

0.2

V

Output voltage high level

V

OUTHI

I

OUTHI

= -2mA

V

VIO

-0.2

V

Input leakage current

I

ILEAK

-10 10

µA

Pullup / pull-down resistors

RPU/RPD

132

166

200

kΩ

Pull-down resistor STANDBY pin

RPD 80

100

120

kΩ

Digital pin capacitance

C

3.5 pF

AIN/IREF input

DC-Characteristics

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

AIN_IREF input resistance to 2.5V
(=5VOUT/2)

R

AIN

Measured to GND
(internalRsense=0)

260

330

400

kΩ

AIN_IREF input voltage range for
linear current scaling

V

AIN

Measured to GND
(IscaleAnalog=1)

0

0.5-2.4

V

5VOUT

/2

V

AIN_IREF open input voltage
level

V

AINO

Open circuit voltage
(internalRsense=0)

V

5VOUT

/2

V

AIN_IREF input resistance to
GND for reference current input

R

IREF

Measured to GND
(internalRsense=1)

0.3

0.45

0.60

kΩ

AIN_IREF current amplification
for reference current to coil
current at maximum setting

I

REFAMPL

I

IREF

= 0.25mA

3000

Times

Motor current full-scale tolerance

-using RDSon measurement
(value for design guideline to
calculate reproduction of certain
motor current & torque)

I

COIL

Internal_Rsense=1,
vsense=0,

I

IREF

= 0.25mA (after
reaching thermal
balance)

-10 +10

%

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 77

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20.3 Thermal Characteristics

The following table shall give an idea on the thermal resistance of the package. The thermal
resistance for a four-layer board will provide a good idea on a typical application. Actual thermal
characteristics will depend on the PCB layout, PCB type and PCB size. The thermal resistance will
benefit from thicker CU (inner) layers for spreading heat horizontally within the PCB. Also, air flow will
reduce thermal resistance.

A thermal resistance of 30K/W for a typical board means, that the package is capable of continuously
dissipating 3.3W at an ambient temperature of 25°C with the die temperature staying below 125°C.
Note, that a thermally optimized layout is required.

Parameter

Symbol

Conditions

Typ

Unit

Typical power dissipation

PD

StealthChop or SpreadCycle, 1.4A RMS
in two phase motor, sinewave, 40 or
20kHz chopper, 24V, 90°C peak surface
of package (motor QSH4218-035-10­027, short time operation)

2.8 W

Typical power dissipation

PD

StealthChop or SpreadCycle, 1.0A RMS
in two phase motor, sinewave, 40 or
20kHz chopper, 24V, 70°C peak surface
of package (motor QSH4218-035-10-

027)

1.4

W

Thermal resistance junction to
ambient on a multilayer board

QFN28

R

TMJA

Dual signal and two internal power
plane board (2s2p) as defined in
JEDEC EIA JESD51-5 and JESD51-7
(FR4, 35µm CU, 70mm x 133mm,
d=1.5mm)

30

K/W

Thermal resistance junction to
case

R

TJC

Junction to heat slug of package

6

K/W

Table 20.1 Thermal characteristics TMC2209

Note

A spread-sheet for calculating TMC2209 power dissipation is available on www.trinamic.com.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 78

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21 Layout Considerations

21.1 Exposed Die Pad

The TMC2209 uses its die attach pad to dissipate heat from the drivers and the linear regulator to the
board. For best electrical and thermal performance, use a reasonable amount of solid, thermally
conducting vias between the die attach pad and the ground plane. The printed circuit board should
have a solid ground plane spreading heat into the board and providing for a stable GND reference.

21.2 Wiring GND

All signals of the TMC2209 are referenced to their respective GND. Directly connect all GND pins under
the device to a common ground area (GND and die attach pad). The GND plane right below the die
attach pad should be treated as a virtual star point. For thermal reasons, the PCB top layer shall be
connected to a large PCB GND plane spreading heat within the PCB.

Attention
Especially the sense resistors are susceptible to GND differences and GND ripple voltage, as the
microstep current steps make up for voltages down to 0.5 mV. No current other than the sense
resistor current should flow on their connections to GND and to the TMC2209. Optimally place them
close to the IC, with one or more vias to the GND plane for each sense resistor. The two sense
resistors for one coil should not share a common ground connection trace or vias, as also PCB traces
have a certain resistance.

21.3 Supply Filtering

The 5VOUT output voltage ceramic filtering capacitor (2.2 to 4.7 µF recommended) should be placed as
close as possible to the 5VOUT pin, with its GND return going directly to the die pad or the nearest
GND pin. This ground connection shall not be shared with other loads or additional vias to the GND
plane. Use as short and as thick connections as possible.

The motor supply pins VS should be decoupled with an electrolytic capacitor (47 μF or larger is
recommended) and a ceramic capacitor, placed close to the device.

Take into account that the switching motor coil outputs have a high dV/dt. Thus capacitive stray into
high resistive signals can occur, if the motor traces are near other traces over longer distances.

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 79

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21.4 Layout Example TMC2209

Schematic

Placement (Excerpt) Top Layout (Excerpt, showing die pad vias)

The complete schematics and layout data for all TMC2209 evaluation boards are available on the
TRINAMIC website. Placement and layout show the more compact routing on TMC2208-EVAL

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 80

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22 Package Mechanical Data

22.1 Dimensional Drawings QFN28

Attention: Drawings not to scale.

Figure 22.1 Dimensional drawings QFN28

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 81

www.trinamic.com

Parameter [mm]

Ref

Min

Nom

Max

total thickness

A

0.8

0.85

0.9

stand off

A1 0 0.035

0.05

mold thickness

A2 0.65

lead frame thickness

A3 0.203

lead width

b

0.2

0.25

0.3

body size X

D 5.0

body size Y

E 5.0

lead pitch

e 0.5

exposed die pad size X *)

J

3.6

3.7

3.8

exposed die pad size Y *)

K

3.6

3.7

3.8

lead length *)

L

0.35

0.4

0.45

package edge tolerance

aaa

0.1

mold flatness

bbb

0.1

coplanarity

ccc

0.08

lead offset

ddd

0.1

exposed pad offset

eee

0.1

*) Attention: These parameters differ to TMC2208 package!
The TMC2209 has a bigger heat-slug than the TMC2208 for better power dissipation. Pad length is
slightly shorter to match this.

22.2 Package Codes

Type

Package

Temperature range

Code & marking

TMC2209-LA

QFN28 (RoHS)

-40°C ... +125°C

TMC2209-LA

TMC… -T

-T suffix denotes tape on reel packed products

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 82

www.trinamic.com

23 Table of Figures

FIGURE 1.1 TMC2209 BASIC APPLICATION BLOCK DIAGRAM ...................................................................................................... 4

FIGURE 1.2 STAND-ALONE DRIVER WITH PRE-CONFIGURATION .................................................................................................... 5

FIGURE 1.3 ENERGY EFFICIENCY WITH COOLSTEP (EXAMPLE) ...................................................................................................... 7

FIGURE 1.4 AUTOMATIC MOTOR CURRENT POWER DOWN .......................................................................................................... 8

FIGURE 2.1 TMC2209 PINNING TOP VIEW – TYPE: QFN28, 5X5MM², 0.5MM PITCH ............................................................... 9

FIGURE 3.1 STANDARD APPLICATION CIRCUIT ........................................................................................................................... 11

FIGURE 3.2 APPLICATION CIRCUIT USING RDSON BASED SENSING ........................................................................................... 12

FIGURE 3.3 5V ONLY OPERATION .............................................................................................................................................. 12

FIGURE 3.4 SIMPLE ESD ENHANCEMENT AND MORE ELABORATE MOTOR OUTPUT PROTECTION .................................................. 14

FIGURE 4.1 ATTACHING THE TMC2209 TO A MICROCONTROLLER UART .................................................................................. 17

FIGURE 4.2 ADDRESSING MULTIPLE TMC2209 VIA SINGLE WIRE INTERFACE USING ANALOG SWITCHES .................................. 18

FIGURE 6.1 MOTOR COIL SINE WAVE CURRENT WITH STEALTHCHOP (MEASURED WITH CURRENT PROBE) .................................. 35

FIGURE 6.2 STEALTHCHOP2 AUTOMATIC TUNING PROCEDURE ................................................................................................... 36

FIGURE 6.3 SCOPE SHOT: GOOD SETTING FOR PWM_REG ....................................................................................................... 38

FIGURE 6.4 SCOPE SHOT: TOO SMALL SETTING FOR PWM_REG DURING AT#2 ....................................................................... 38

FIGURE 6.5 SUCCESSFULLY DETERMINED PWM_GRAD(_AUTO) AND PWM_OFS(_AUTO) ................................................... 38

FIGURE 6.6 VELOCITY BASED PWM SCALING (PWM_AUTOSCALE=0) ......................................................................................... 40

FIGURE 6.7 TPWMTHRS FOR OPTIONAL SWITCHING TO SPREADCYCLE ................................................................................... 41

FIGURE 7.1 CHOPPER PHASES ................................................................................................................................................... 45

FIGURE 7.2 NO LEDGES IN CURRENT WAVE WITH SUFFICIENT HYSTERESIS (MAGENTA: CURRENT A, YELLOW & BLUE: SENSE

RESISTOR VOLTAGES A AND B) ......................................................................................................................................... 47

FIGURE 7.3 SPREADCYCLE CHOPPER SCHEME SHOWING COIL CURRENT DURING A CHOPPER CYCLE ............................................ 48

FIGURE 9.1 SCALING THE MOTOR CURRENT USING THE ANALOG INPUT...................................................................................... 52

FIGURE 11.1 FUNCTION PRINCIPLE OF STALLGUARD4 .............................................................................................................. 55

FIGURE 12.1 COOLSTEP ADAPTS MOTOR CURRENT TO THE LOAD ............................................................................................... 58

FIGURE 13.1 STEP AND DIR TIMING, INPUT PIN FILTER ......................................................................................................... 60

FIGURE 13.2 MICROPLYER MICROSTEP INTERPOLATION WITH RISING STEP FREQUENCY (EXAMPLE: 16 TO 256) ..................... 62

FIGURE 13.3 INDEX SIGNAL AT POSITIVE ZERO TRANSITION OF THE COIL A SINE CURVE .......................................................... 63

FIGURE 14.1 SOFTWARE GENERATED MOTION PROFILE ............................................................................................................. 64

FIGURE 15.1 DIAG AND INDEX OUTPUTS ............................................................................................................................... 66

FIGURE 16.1 CURRENT SETTING AND FIRST STEPS WITH STEALTHCHOP .................................................................................... 67

FIGURE 16.2 TUNING STEALTHCHOP AND SPREADCYCLE .......................................................................................................... 68

FIGURE 16.3 CONFIGURATION FOR COOLSTEP IN STEALTHCHOP MODE .................................................................................... 69

FIGURE 16.4 OTP PROGRAMMING ............................................................................................................................................ 70

FIGURE 22.1 DIMENSIONAL DRAWINGS QFN28 ....................................................................................................................... 80

TMC2209 DATASHEET (Rev. 1.05 / 2020-MAY-18) 83

www.trinamic.com

24 Revision History

Version

Date

Author

BD= Bernhard Dwersteg

Description

V0.05

2018-Dec-04

BD

Preliminary work

V0.06

2019-Feb-04

BD

Updated electrical data as measured on samples

V0.1

2019-Feb-11

BD

Finished preliminary datasheet

V0.90

2019-Feb-12

BD

Standby current, new Eval-Board added

V1.00

2019-Feb-28

BD

Hints for coolStep

V1.01

2019-Apr-26

BD

Corrected table of microstep pin settings

V1.02

2019-May-14

BD

Relaxed spec concerning voltage limit up to 33V

V1.03

2019-Jun-25

BD

Hint for StealthChop IRUN must be >=8

V1.04

2020-Feb-19

BD

Hint for IRUN in combination with CoolStep

V1.05

2020-May-18

BD

Minor corrections, Logo

Table 24.1 Document Revisions

25 References

[TMC2209-EVAL] TMC22xx Evaluation board: Manuals, software and PCB data available on

www.trinamic.com

[AN001] Trinamic Application Note 001 - Parameterization of SpreadCycle™,

www.trinamic.com

Calculation sheet

TMC2209_Calculations.xlsx www.trinamic.com