ST L6474 User Manual

easySPIN – fully integrated microstepping motor driver

Features

■ Operating voltage: 8 - 45 V

■ 7.0 A output peak current (3.0 A r.m.s.)

■ Low R

■ Programmable power MOS slew-rate

■ Up to 1/16 microstepping

■ Current control with adaptive decay

■ Non dissipative current sensing

■ SPI interface

■ Low quiescent and standby currents

■ Programmable non dissipative overcurrent

protection on all power MOS

■ Two-level overtemperature protection

Application

■ Bipolar stepper motor

power MOSFETS

DSon

L6474

POWERSO36

an adaptive decay mode which outperforms
traditional implementations.

All data registers, including those used to set
analogue values (i.e. current control value,
current protection trip point, dead time, etc.) are
sent through a standard 5 Mbit/s SPI.

A very rich set of protections (thermal, low bus
voltage, overcurrent) makes the L6474 “bullet
proof” as required by the most demanding motor
control applications.

HTSSOP28

Description

The L6474, realized in analog mixed signal
technology, integrates a dual low R
full bridge with all power switches equipped with
an accurate on-chip current sensing circuitry
suitable for non dissipative current control and
overcurrent protections. Thanks to a new current
control, a 1/16 microstepping is achieved through

Table 1. Device summary

Order codes Package Packing

L6474H HTSSOP28 Tube

L6474HTR HTSSOP28 Tape and reel

L6474PD POWERSO36 Tube

L6474PDTR POWERSO36 Tape and reel

December 2011 Doc ID 022529 Rev 2 1/51

DSon

DMOS

www.st.com

51

Contents L6474

Contents

1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2 Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.3 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.1 Pin list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5 Typical applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6 Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

6.1 Device power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

6.2 Logic I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

6.3 Charge pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

6.4 Microstepping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6.5 Absolute position counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.6 Step sequence control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.7 Enable and disable commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.8 Internal oscillator and oscillator driver . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.8.1 Internal oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.8.2 External clock source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.9 Overcurrent detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6.10 Undervoltage lock-out (UVLO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

6.11 Thermal warning and thermal shutdown . . . . . . . . . . . . . . . . . . . . . . . . . 23

6.12 Reset and standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

6.13 Programmable DMOS slew-rate, dead-time and blanking-time . . . . . . . . 24

6.14 Integrated analog to digital converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

6.15 Internal voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2/51 Doc ID 022529 Rev 2

L6474 Contents

6.16 SYNC pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.17 FLAG pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

7 Phase current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

7.1 Peak current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

7.2 Auto-adjusted decay mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

7.3 Auto-adjusted fast decay during the falling steps . . . . . . . . . . . . . . . . . . . 28

7.4 Torque regulation (output current amplitude regulation) . . . . . . . . . . . . . . 29

8 Serial interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

9 Programming manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

9.1 Registers and flags description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

9.1.1 ABS_POS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

9.1.2 EL_POS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

9.1.3 MARK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

9.1.4 TVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

9.1.5 T_FAST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

9.1.6 TON_MIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

9.1.7 TOFF_MIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

9.1.8 ADC_OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

9.1.9 OCD_TH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

9.1.10 STEP_MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

9.1.11 ALARM_EN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

9.1.12 CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

9.1.13 STATUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

9.2 Application commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

9.2.1 Command management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

9.2.2 Nop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

9.2.3 SetParam (PARAM, VALUE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

9.2.4 GetParam (PARAM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

9.2.5 Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

9.2.6 Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

9.2.7 GetStatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

10 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

11 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Doc ID 022529 Rev 2 3/51

List of tables L6474

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Table 2. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Table 3. Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 4. Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 5. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Table 6. Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 7. Typical application values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 8. CL values according to external oscillator frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 9. Registers map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 10. EL_POS register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 11. Torque regulation by TVAL_HOLD, TVAL_ACC, TVAL_DEC and TVAL_RUN registers . 34

Table 12. T_FAST register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 13. Maximum fast decay times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 14. Minimum ON time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 15. Minimum OFF time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 16. ADC_OUT value and torque regulation feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 17. Overcurrent detection threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 18. STEP_MODE register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Table 19. Step mode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Table 20. SYNC signal source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Table 21. ALARM_EN register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 22. CONFIG register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 23. Oscillator management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Table 24. Overcurrent event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Table 25. Programmable power bridge output slew-rate values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 26. External torque regulation enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 27. Switching period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 28. STATUS register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 29. STATUS register DIR bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table 30. Application commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table 31. Nop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Table 32. SetParam command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Table 33. GetParam command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Table 34. HardStop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 35. Disable command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 36. GetStatus command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 37. HTSSOP28 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Table 38. POWERSO36 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 39. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

4/51 Doc ID 022529 Rev 2

L6474 List of figures

List of figures

Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 2. HTSSOP28 pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 3. POWERSO36 pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 4. Bipolar stepper motor control application using L6474 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 5. Charge pump circuitry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 6. Normal mode and microstepping (16 microsteps) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 7. OSCIN and OSCOUT pin configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 8. Internal 3 V linear regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 9. Peak current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 10. Adaptive decay - fast decay tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 11. Adaptive decay - switch from normal to slow+fast decay mode and vice versa . . . . . . . . . 28

Figure 12. Fast decay tuning during the falling steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 13. SPI timings diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 14. Daisy-chain configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 15. Command with three-byte argument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Figure 16. Command with three-byte response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Figure 17. Command response aborted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Figure 18. HTSSOP28 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Figure 19. POWERSO36 drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Doc ID 022529 Rev 2 5/51

Block diagram L6474

1 Block diagram

Figure 1. Block diagram

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6/51 Doc ID 022529 Rev 2

L6474 Electrical data

2 Electrical data

2.1 Absolute maximum ratings

Table 2. Absolute maximum ratings

Symbol Parameter Test condition Value Unit

VDD Logic interface supply voltage 5.5 V

VS Motor supply voltage VSA = VSB = VS 48 V

Differential voltage between AGND,

V

V

V

V

I

out_peak

1. Maximum output current limit is related to metal connection and bonding characteristics. Actual limit must satisfy maximum
thermal dissipation constraints.

2. TBD.

GND, diff

V

boot

V

REG

ADCIN

V

OSC

out_diff

LOGIC

I

out

T

OP

T

P

tot

PGND and DGND

Bootstrap peak voltage 55 V

Internal voltage regulator output pin
and logic supply voltage

Integrated ADC input voltage range
(ADCIN pin)

OSCIN and OSCOUT pin voltage
range

Differential voltage between V

, OUT2A, PGND and VSB,

OUT1

A

OUT1

, OUT2B, PGND pins

B

SA

,

= VSB = VS 48 V

V

SA

Logic inputs voltage range -0.3 to +5.5 V

(1)

R.m.s. output current 3 A

(1)

Pulsed output current T

< 1 ms 7 A

PULSE

Operating junction temperature 150 °C

Storage temperature range -55 to 150 °C

s

Total power dissipation (TA = 25 ºC)

(2)

±0.3 V

3.6 V

-0.3 to +3.6 V

-0.3 to +3.6 V

TBD W

Doc ID 022529 Rev 2 7/51

Electrical data L6474

2.2 Recommended operating conditions

Table 3. Recommended operating conditions

Symbol Parameter Test condition Value Unit

V

Logic interface supply voltage

DD

V

Motor supply voltage VSA = VSB = VS 8 45 V

S

Differential voltage between

, OUT1A, OUT2A, PGND

V

V

out_diff

SA

and V

, OUT1B, OUT2B,

SB

PGND pins

V

Logic supply voltage

REG,in

Integrated ADC input voltage

V

ADC

(ADCIN pin)

Operating junction temperature -25 125 °C

T

j

2.3 Thermal data

Table 4. Thermal data

Symbol Parameter Package Typ Unit

R

thJA

1. TBD.

2. TBD.

Thermal resistance junction-ambient

3.3 V logic outputs 3.3 V

5 V logic outputs 5

V

= V

SA

V

REG

external source

= VS 45 V

SB

voltage imposed by

HTSSOP28

POWERSO36

3.2 3.3 V

TBD

TBD

REG

V

°C/W

0 V

(1)

(2)

8/51 Doc ID 022529 Rev 2

L6474 Electrical characteristics

3 Electrical characteristics

VSA = VSB = 36 V; VDD = 3.3 V; internal 3 V regulator; TJ = 25 °C, unless otherwise
specified.

Table 5. Electrical characteristics

Symbol Parameter Test condition Min. Typ. Max. Unit

General

V

SthOn

V

SthOff

V

SthHyst VS

I

q

T

j(WRN)

T

j(SD)

VS UVLO turn-on threshold 7.5 8.2 8.9 V

VS UVLO turn-off threshold 6.6 7.2 7.8 V

UVLO threshold hysteresis 0.7 1 1.3 V

Quiescent motor supply current

Thermal warning temperature 130 °C

Thermal shutdown temperature 160 °C

Charge pump

Voltage swing for charge pump oscillator 10 V

V

pump

f

pump,min

f

pump,max

I

boot

Minimum charge pump oscillator frequency

(1)

Maximum charge pump oscillator frequency

(1)

Average boot current

Output DMOS transistor

High side switch ON resistance

R

DS(on)

Low side switch ON resistance

I

DSS

t

Leakage current

Rise time

r

(3)

Internal oscillator selected;
V

= 3.3 V ext; CP

REG

floating

= f

f

sw,A

= 15.6 kHz

sw,B

POW_SR = ‘10’

= 25 °C, I

T

j

T

= 125 °C,

j

T

= 25 °C, I

j

= 125 °C,

T

j

OUT = V

= 3A 0.37

out

(2)

I

= 3A 0.51

out

= 3A 0.18

out

(2)

I

= 3A 0.23

out

S

OUT = GND -0.3

POW_SR = '00', I

POW_SR = '00', I

POW_SR = ‘11’, I

POW_SR = ‘10’, I

POW_SR = ‘01’, I

= +1A 100

out

= -1A 80

out

= ±1A 100

out

= ±1A 200

out

= ±1A 300

out

0.5 0.65 mA

660 kHz

800 kHz

1.1 1.4 mA

Ω

3.1
mA

ns

Doc ID 022529 Rev 2 9/51

Electrical characteristics L6474

Table 5. Electrical characteristics (continued)

Symbol Parameter Test condition Min. Typ. Max. Unit

(3)

SR

SR

t

f

out_r

out_f

Fall time

Output rising slew-rate

Output falling slew-rate

Dead time and blanking

POW_SR = '00'; I

POW_SR = '00'; I

POW_SR = ‘11’, I

POW_SR = ‘10’, I

POW_SR = ‘01’, I

POW_SR = '00', I

POW_SR = '00', I

POW_SR = ‘11’, I

POW_SR = ‘10’, I

POW_SR = ‘01’, I

POW_SR = '00', I

POW_SR = '00', I

POW_SR = ‘11’, I

POW_SR = ‘10’, I

POW_SR = ‘01’, I

= +1A 90

out

= -1A 110

out

= ±1A 110

out

= ±1A 260

out

= ±1A 375

load

= +1A 285

out

= -1A 360

out

= ±1A 285

out

= ±1A 150

out

= ±1A 95

out

= +1A 320

out

= -1A 260

out

= ±1A 260

out

= ±1A 110

out

= ±1A 75

out

POW_SR = '00' 250

ns

V/µs

V/µs

t

DT

t

blank Blanking time

Dead time

Source-drain diodes

High side diode forward ON voltage I

V

SD,HS

V

Low side diode forward ON voltage I

SD,LS

t

rrHS

t

rrLS

High side diode reverse recovery time I

Low side diode reverse recovery time I

(1)

(1)

POW_SR = ‘11’,

= 16 MHz

f

OSC

POW_SR = ‘10’,
f

= 16 MHz

OSC

POW_SR = ‘01’,

= 16 MHz

f

OSC

375

625

875

POW_SR = '00' 250

POW_SR = ‘11’,

= 16 MHz

f

OSC

POW_SR = ‘10’,

= 16 MHz

f

OSC

POW_SR = ‘01’,
f

= 16 MHz

OSC

= 1 A 1 1.1 V

out

= 1 A 1 1.1 V

out

= 1 A 30 ns

out

= 1 A 100 ns

out

375

625

875

ns

ns

10/51 Doc ID 022529 Rev 2

L6474 Electrical characteristics

Table 5. Electrical characteristics (continued)

Symbol Parameter Test condition Min. Typ. Max. Unit

Logic inputs and outputs

V

Low logic level input voltage 0.8 V

IL

V

High logic level input voltage 2 V

IH

I

IH

I

IL

V

OL

High logic level input current

Low logic level input current

Low logic level output voltage

VOH High logic level output voltage

RPU
R

R

PUDIR

I

logic

PD

CS pull-up and STBY pull-down resistors

DIR input pull-up resistance DIR = GND 60 85 110 kΩ

Internal logic supply current

(4)

V

(5)

(6)

= 5 V 1 µA

IN

V

= 0 V -1 µA

IN

VDD = 3.3 V, IOL = 4 mA 0.3

VDD = 5 V, IOL = 4 mA 0.3

V

= 3.3 V, IOH = 4 mA 2.4

DD

= 5 V, IOH = 4 mA 4.7

V

DD

= GND;

CS
STBY/RST

3.3 V V

= 5 V

externally

REG

supplied, internal oscillator

335 430 565 kΩ

3.7 4.3 mA

V

V

I

logic,STBY

f

Standby mode internal logic supply current

Step clock input frequency 2 MHz

STCK

Internal oscillator and external oscillator driver

Internal oscillator frequency T

f

osc,i

f

Programmable external oscillator frequency 8 32 MHz

osc,e

V

OSCOUTH

V

OSCOUTL

t

rOSCOUT

t

fOSCOUT

t

t

OSCOUT clock source high level voltage

OSCOUT clock source low level voltage

OSCOUT clock source rise and fall time Internal oscillator 20 ns

Internal to external oscillator switching delay 3 ms

extosc

intosc

External to internal oscillator switching delay 1.5 µs

SPI

f

Maximum SPI clock frequency

CK,MAX

t

rCK

t

fCK

t

hCK

t

lCK

t

setCS

SPI clock rise and fall time

SPI clock high and low time

Chip select set-up time

(7)

(7)

(7)

(7)

3.3 V V
supplied

= 25 °C, V

j

externally

REG

REG

2 2.5 µA

= 3.3 V -3% 16 +3% MHz

Internal oscillator 3.3 V
V

externally supplied;

REG

I

OSCOUT

= 4 mA

2.4 V

Internal oscillator 3.3 V
V

externally supplied;

REG

I

OSCOUT

= 4 mA

0.3 V

5 MHz

CL = 30 pF 25 ns

75 ns

350 ns

Doc ID 022529 Rev 2 11/51

Electrical characteristics L6474

Table 5. Electrical characteristics (continued)

Symbol Parameter Test condition Min. Typ. Max. Unit

(7)

(7)

10 ns

800 ns

(7)

(7)

(7)

(7)

(7)

(7)

37 ns

25 ns

20 ns

38 ns

47 ns

57 ns

t

Chip select hold time

holCS

t

Deselect time

disCS

t

setSDI

t

holSDI

t

enSDO

t

disSDO

t

vSDO

t

holSDO

Data input set-up time

Data input hold time

Data output enable time

Data output disable time

Data output valid time

Data output hold time

Current control

I

STEP,max

I

STEP,m in

Max. programmable reference current 4 A

Min. programmable reference current 31 mA

Overcurrent protection

I

OCD,MAX

I

OCD,MIN

I

OCD,RES

t

OCD,Flag

t

OCD,SD

Maximum programmable overcurrent
detection threshold

Minimum programmable overcurrent
detection threshold

Programmable overcurrent detection
threshold resolution

OCD to flag signal delay time dI

OCD to shut down delay time

Standby

qSTBY

t

STBY,min

t

logicwu

t

cpwu

conditions

Minimum standby time 10 µs

Logic power-on and wake-up time 38 45 µs

Charge pump power-on and wake-up time

Quiescent motor supply current in standby

I

Internal voltage regulator

OCD_TH = ‘1111’ 6 A

OCD_TH = ‘0000’ 0.375 A

0.375 A

= 350A/µs 650 1000 ns

out/dt

= 350A/µs

dI

out/dt

POW_SR = '10'

V

= 8 V 26 34

S

S = 36 V 30 36

V

Power bridges disabled, C
= 10 nF, C

= 220 nF

boot

p

600 µs

µA

650 µs

Voltage regulator output voltage 2.9 3 3.2 V

V

REG

I

Voltage regulator output current 40 mA

REG

V

REG, drop

I

REG,STBY

Voltage regulator output voltage drop I

= 40 mA 50 mV

REG

Voltage regulator standby output current 10 mA

Integrated analog to digital converter

Analog to digital converter resolution 5 bit

N

ADC

12/51 Doc ID 022529 Rev 2

L6474 Electrical characteristics

Table 5. Electrical characteristics (continued)

Symbol Parameter Test condition Min. Typ. Max. Unit

V

1. Accuracy depends on oscillator frequency accuracy.

2. Tested at 25 °C in a restricted range and guaranteed by characterization.

3. Rise and fall time depends on motor supply voltage value. Refer to SR

4. Not valid for STBY/RST

5. Not valid for SW and CS pins which have internal pull-up resistor.

6. FLAG

7. See Figure 13– SPI timings diagram for details.

Analog to digital converter reference voltage V

ADC,ref

f

S

rise and fall time.

Analog to digital converter sampling
frequency

out

pins which have internal pull-down resistor.

and SYNC open drain outputs included.

V

REG

f

/

OSC

512

values (Table 5) in order to evaluate the actual

kHz

Doc ID 022529 Rev 2 13/51

Pin connection L6474

4 Pin connection

Figure 2. HTSSOP28 pin connection (top view)

RST

DIR

Figure 3. POWERSO36 pin connection (top view)

74"

74"

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14/51 Doc ID 022529 Rev 2

L6474 Pin connection

4.1 Pin list

Table 6. Pin description

N. Name Type Function

17 VDD Power Logic outputs supply voltage (pull-up reference)

6 VREG Power

7 OSCIN Analog input

Internal 3 V voltage regulator output and 3.3 V external logic
supply

Oscillator pin 1. To connect an external oscillator or clock source.
If this pin is unused, it should be left floating.

Oscillator pin 2. To connect an external oscillator. When the

8 OSCOUT Analog output

internal oscillator is used this pin can supply 2/4/8/16 MHz. If this
pin is unused, it should be left floating.

10 CP Output Charge pump oscillator output

11 VBOOT Supply voltage

Bootstrap voltage needed for driving the high side power DMOS of
both bridges (A and B)

5 ADCIN Analog input Internal analog to digital converter input

2

VSA Power supply Full bridge A power supply pin. It must be connected to VSB

26

12

VSB Power supply Full bridge B power supply pin. It must be connected to VSA

16

27

PGND Ground Power ground pin

13

1 OUT1A Power output Full bridge A output 1

28 OUT2A Power output Full bridge A output 2

14 OUT1B Power output Full bridge B output 1

15 OUT2B Power output Full bridge B output 2

9 AGND Ground Analog ground

4 DIR Logical input Direction input

21 DGND Ground Digital ground

22 SYNC Open drain output Synchronization signal.

18 SDO Logic output Data output pin for serial interface

20 SDI Logic input Data input pin for serial interface

19 CK Logic input Serial interface clock

23 CS Logic input Chip select input pin for serial interface

Status flag pin. An internal open drain transistor can pull the pin to

24 FLAG Open drain output

GND when a programmed alarm condition occurs (step loss,
OCD, thermal pre-warning or shutdown, UVLO, wrong command,
non performable command)

Standby and reset pin. LOW logic level resets the logic and puts

3 STBY\RST

Logic input

the device into standby mode. If not used, should be connected to
VDD

Doc ID 022529 Rev 2 15/51

Pin connection L6474

Table 6. Pin description (continued)

N. Name Type Function

25 STCK Logic input Step clock input

EPAD Exposed pad Ground Internally connected to PGND, AGND and DGND pins

16/51 Doc ID 022529 Rev 2