Datasheet tda5142t DATASHEETS (Philips)

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INTEGRATED CIRCUITS

DATA SH EET

TDA5142T

Brushless DC motor drive circuit

Product speciﬁcation Supersedes data of March 1992 File under Integrated Circuits, IC11

Philips Semiconductors

June 1994

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

FEATURES

• Full-wave commutation without position sensors

• Built-in start-up circuitry

• Six outputs that can drive three external transistor pairs:

APPLICATIONS

• High-power applications e.g.: – high-end hard disk drives – automotive.

– output current 0.2 A (typ.) – low saturation voltage – built-in current limiter

GENERAL DESCRIPTION

The TDA5142T is a bipolar integrated circuit used to drive 3-phase brushless DC motors in full-wave mode. The

• Thermal protection

• Tacho output without extra sensor

device is sensorless (saving of 3 hall-sensors) using the back-EMF sensing technique to sense the rotor position. It includes a brake function and 6 pre-drivers able to

• Transconductance amplifier for an external control transistor

• Motor brake facility.

control FETs or bipolar external transistors. It is ideally suited for high-power applications such as high-end hard disk drives, automotive and other applications.

QUICK REFERENCE DATA

Measured over full voltage and temperature range.

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

VMOT

supply voltage note 1 4 − 18 V input voltage to the output

3 − 18 V

driver stages

LIM

driver output voltage IO= 100 mA; lower transistor −−0.35 V

= 100 mA; upper transistor 1.05 −−V

current limiting V

= 14.5 V; RO=47Ω 150 200 250 mA

VMOT

Note

1. An unstabilized supply can be used.

ORDERING INFORMATION

PACKAGE

TYPE NUMBER

PINS PIN POSITION MATERIAL CODE

TDA5142T 24 SOL plastic SOT137-1

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Philips Semiconductors Product speciﬁcation

BBB

BBBB

BBB

B B

BB BB

BBBBBBB

B B B B B B

Brushless DC motor drive circuit TDA5142T

BLOCK DIAGRAM

BBBBBB

B B

BBBB BBBB BBBB BBBB BBBB BBBB

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Fig.1 Block diagram.

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

PINNING

SYMBOL PIN DESCRIPTION

OUT-NB 1 driver output B for driving the n-channel power FET or power NPN OUT-PB 2 driver output B for driving the n-channel power FET or power PNP GND1 3 ground (0 V) motor supply return for output stages OUT-PC 4 driver output C for driving the n-channel power FET or power PNP OUT-NC 5 driver output C for driving the n-channel power FET or power NPN VMOT 6 input voltage for the output driver stages TEST 7 test input/output BRAKE 8 brake input FG 9 frequency generator: output of the rotation speed detector stage GND2 10 ground supply return for control circuits V

CAP-CD 12 external capacitor connection for adaptive communication delay timing CAP-DC 13 external capacitor connection for adaptive communication delay timing copy CAP-ST 14 external capacitor connection for start-up oscillator CAP-TI 15 external capacitor connection for timing +AMP IN 16 non-inverting input of the transconductance ampliﬁer

−AMP IN 17 inverting input of the transconductance ampliﬁer AMP OUT 18 transconductance ampliﬁer output (open collector) COMP-A 19 comparator input corresponding to output A COMP-B 20 comparator input corresponding to output B COMP-C 21 comparator input corresponding to output C MOT0 22 input from the star point of the motor coils OUT-NA 23 driver output A for driving the n-channel power FET or power NPN OUT-PA 24 driver output A for driving the n-channel power FET or power PNP

11 supply voltage

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

FUNCTIONAL DESCRIPTION

The TDA5142T offers a sensorless three phase motor drive function. It is unique in its combination of sensorless motor drive and full-wave drive. The TDA5142T offers protected outputs capable of driving external power FETs or bipolar power transistors. It can easily be adapted for different motors and applications. The TDA5142T offers the following features:

• Sensorless commutation by using the motor EMF.

• Built-in start-up circuit.

• Optimum commutation, independent of motor type or

motor loading.

• Six output drivers.

• Maximum output current 0.25 A.

• Outputs protected by current limiting and thermal

protection.

• Low current consumption.

• Accurate frequency generator (FG) by using the

motor EMF.

• Brake function.

• Uncommitted operational transconductance amplifier

(OTA), with a high output current, for use as a control

Fig.2 Pin configuration.

amplifier or as a level shifter in a Switched Mode Power Supply (SMPS) drive.

LIMITING VALUES

In accordance with the Absolute Maximum Rating System (IEC 134).

SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT

supply voltage 4 18 V input voltage; all pins except

VI< 18 V −0.3 VP + 0.5 V

VMOT

VMOT input voltage 3 18 V output voltage

FG GND V

V AMP OUT − 18 V OUT-NA, OUT-NB and OUT-NC − V

VMOT

− 0.9 V

OUT-PA, OUT-PB and OUT-PC 0.2 − V

input voltage CAP-ST, CAP-TI,

− 2.5 V

CAP-CD and CAP-DC

stg

amb

tot

storage temperature −55 +150 °C operating ambient temperature 0 +70 °C total power dissipation see Fig.3 −− W electrostatic handling see Chapter “Handling” − 500 V

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

HANDLING

MLB777

T ( C)

amb

Every pin withstands the ESD test according to

“MIL-STD-883C class 2”

. Method 3015 (HBM 1500 Ω, 100 pF) 3 pulses + and 3 pulses − on each pin referenced to ground.

P (W)

tot

0 200

50 100 150

Fig.3 Power derating curve.

CHARACTERISTICS

= 14.5 V; T

=25°C; unless otherwise speciﬁed.

amb

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

Supply

VMOT

supply voltage note 1 4 − 18 V supply current note 2 − 5.2 6.25 mA input voltage to the output driver

see Fig.1 3 − 18 V

stages

Thermal protection

local temperature at temperature

130 140 150 °C

sensor causing shut-down

∆T reduction in temperature before

after shut-down − T

− 30 − K

switch-on

COMP-A, COMP-B, COMP-C and MOT0

V I

V ∆V

CSW

input voltage −0.5 − V input bias current 0.5 V < VI< V

− 1.5 V −10 − 0 µA

VMOT

comparator switching level note 3 ±20 ±25 ±30 mV variation in comparator switching

−3 0 +3 mV

levels

hys

comparator input hysteresis − 75 −µV

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Brushless DC motor drive circuit TDA5142T

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

OUT-NA, OUT-NB, OUT-NC, OUT-PA, OUT-PB and OUT-PC

∆V

LIM

O-n

O-p

n-channel driver output voltage upper transistor;

IO= −100 mA lower transistor;

=10mA

p-channel driver output voltage upper transistor;

IO= −10 mA lower transistor;

= 100 mA

variation in saturation voltage

IO= 100 mA −− 180 mV

between lower transistors variation in saturation voltage

IO= −100 mA −− 180 mV

between upper transistors current limiting V

VMOT

= 14.5 V;

RO=47Ω

−1.05 −−V

−− 0.35 V

−1.05 −−V

−− 0.35 V

150 200 250 mA

+AMP IN and −AMP IN

input voltage −0.3 − VP− 1.7 V differential mode voltage without

‘latch-up’

offset

input bias current −− 650 nA input capacitance − 4 − pF input offset voltage −− 10 mV

AMP OUT (open collector)

I V V

sink

sat O

output sink current 40 −−mA saturation voltage II=40mA − 1.5 2.1 V

output voltage −0.5 − +18 V SR slew rate R G

transfer gain 0.3 −−S

BRAKE

brake-mode voltage enable brake mode;

input current brake mode −−20 −30 µA

−− ±V

= 330 Ω; CL=50pF 40 −−mA/µs

− 2.3 V

4V<VP<18V normal mode;

4V<V

<18V

2.7 − V

normal mode − 020µA

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

FG (push-pull)

THL

CAP-ST

sink

source

SWL

SWH

CAP-TI

sink

source

SWL

SWM

SWH

CAP-CD

sink

source

sink/Isource

CAP-DC

sink

source

sink/Isource

Notes

1. An unstabilized supply can be used.

2. V

3. Switching levels with respect to driver outputs OUT-NA, OUT-NB, OUT-NC, OUT-PA, OUT-PB and OUT-PC.

LOW level output voltage IO= 1.6 mA −− 0.4 V

HIGH level output voltage IO= −60 µAV

−0.3 − V

HIGH-to-LOW transition time CL= 50 pF; RL=10kΩ− 0.5 −µs

ratio of FG frequency and

− 1 −

commutation frequency

output sink current 1.5 2.0 2.5 µA

output source current −2.5 −2.0 −1.5 µA

LOW level switching voltage − 0.20 − V

HIGH level switching voltage − 2.20 − V

output sink current − 28 −µA

output source current 0.2 V < V

0.3V<V

< 0.3 V −−57 −µA

CAP-TI

< 2.2 V −−5−µA

CAP-TI

LOW level switching voltage − 50 − mV

MIDDLE level switching voltage − 0.30 − V

HIGH level switching voltage − 2.20 − V

output sink current 10.6 16.2 22 µA

output source current −5.3 −8.1 −11 µA

ratio of sink to source current 1.85 2.05 2.25

LOW level input voltage 850 875 900 mV

HIGH level input voltage 2.3 − 2.5 V

output sink current 10.1 15.5 20.9 µA

output source current −20.9 −15.5 −10.1 µA

ratio of sink to source current 0.9 1.025 1.15

LOW level input voltage 850 875 900 mV

HIGH level input voltage 2.3 − 2.5 V

VMOT=VP

, all other inputs at 0 V; all outputs at VP; IO= 0 mA.

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Philips Semiconductors Product speciﬁcation

B B

Brushless DC motor drive circuit TDA5142T

APPLICATION INFORMATION

BBBBBBBBBBB BBBBBBBBBBB

(1) RX = RY > 8 (VMOT − 1.5)

Fig.4 Application diagram without use of the operational transconductance amplifier (OTA) with bipolar

power transistors.

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Philips Semiconductors Product speciﬁcation

B B

Brushless DC motor drive circuit TDA5142T

BBBBBBBBBBB BBBBBBBBBBB

Fig.5 Application diagram without use of the operational transconductance amplifier (OTA)

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with MOSFETs.

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

Introduction (see Fig.6)

Full-wave driving of a three phase motor requires three push-pull output stages. In each of the six possible states two outputs are active, one sourcing (H) and one sinking (L). The third output presents a high impedance (Z) to the motor, which enables measurement of the motor back-EMF in the corresponding motor coil by the EMF comparator at each output. The commutation logic is responsible for control of the output transistors and selection of the correct EMF comparator. In Table 1 the sequence of the six possible states of the external connected output transistors has been depicted and the corresponding output levels on the NA, PA, NB, PB, NC and PC outputs of the TDA5142T.

The zero-crossing in the motor EMF (detected by the comparator selected by the commutation logic) is used to calculate the correct moment for the next commutation, that is, the change to the next output state. The delay is calculated (depending on the motor loading) by the adaptive commutation delay block.

The output stages are also protected by a current limiting circuit and by thermal protection.

The detected zero-crossings are used to provide speed information. The information has been made available on the FG output pin. This output provides an output signal with a frequency equal to the commutation frequency.

The system will only function when the EMF voltage from the motor is present. Therefore, a start oscillator is provided that will generate commutation pulses when no zero-crossings in the motor voltage are available.

A timing function is incorporated into the device for internal timing and for timing of the reverse rotation detection.

The TDA5142T also contains an uncommitted transconductance amplifier (OTA) that can be used as a control amplifier. The output is capable of directly driving an external power transistor.

The TDA5142T is designed for systems with low current consumption: use of I

L logic, adaptive base drive for the

output transistors (patented).

Adjustments

The system has been designed in such a way that the tolerances of the application components are not critical. However, the approximate values of the following components must still be determined:

• The start capacitor; this determines the frequency of the start oscillator.

• The two capacitors in the adaptive commutation delay circuit; these are important in determining the optimum moment for commutation, depending on the type and loading of the motor.

• The timing capacitor; this provides the system with its timing signals.

HE START CAPACITOR (CAP-ST)

T This capacitor determines the frequency of the start

oscillator. It is charged and discharged, with a current of 2 µA, from 0.05 to 2.2 V and back to 0.05 V. The time taken to complete one cycle is given by: t

= (2.15 × C) s (with C in µF)

start

The start oscillator is reset by a commutation pulse and so is only active when the system is in the start-up mode. A pulse from the start oscillator will cause the outputs to change to the next state (torque in the motor).

Table 1 Output states.

STATE MOT1

(1)

1ZLHLHHHLL 2HLLLHHZLH 3HLLZLHLHH 4Z L H H L L L H H 5LHHHL LZLH 6LHHZLHHLL

Note

1. H = HIGH state; L = LOW state; Z = high-impedance OFF-state.

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OUT-

(1)

OUT-

(1)

MOT2

(1)

OUT-

(1)

OUT-

(1)

MOT3

(1)

OUT-

(1)

OUT-

(1)

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

If the movement of the motor generates enough EMF the TDA5142T will run the motor. If the amount of EMF generated is insufficient, then the motor will move one step only and will oscillate in its new position. The amplitude of the oscillation must decrease sufficiently before the arrival of the next start pulse, to prevent the pulse arriving during the wrong phase of the oscillation. The oscillation of the motor is given by:

osc

where:

= torque constant (N.m/A)

I = current (A) p = number of magnetic pole-pairs J = inertia J (kg.m2).

---------------------------------- K

I× p×

2π

---------------------- -

Example: J = 72 × 10−6kg.m2, K = 25 × 10−3N.m/A,p=6 and I = 0.5 A; this gives f

= 5 Hz. If the damping is high

osc

then a start frequency of 2 Hz can be chosen or t = 500 ms, thus C = 0.5/2 = 0.25 µF (choose 220 nF).

HE ADAPTIVE COMMUTATION DELAY (CAP-CD AND

T CAP-DC)

In this circuit capacitor CAP-CD is charged during one commutation period, with an interruption of the charging current during the diode pulse. During the next commutation period this capacitor (CAP-CD) is discharged at twice the charging current. The charging current is

8.1 µA and the discharging current 16.2 µA; the voltage range is from 0.9 to 2.2 V. The voltage must stay within this range at the lowest commutation frequency of interest, f

8.1 10

------------------------- f1.3×

6–

6231

(C in nF)

------------ f

If the frequency is lower, then a constant commutation delay after the zero-crossing is generated by the discharge from 2.2 to 0.9 V at 20 µA; maximum delay = (0.076 × C) ms (with C in nF)

Example: nominal commutation frequency = 900 Hz and the lowest usable frequency = 400 Hz; so:

CAP-CD

6231

------------ 400

The other capacitor, CAP-DC, is used to repeat the same delay by charging and discharging with 15.5 µA. The same value can be chosen as for CAP-CD. Figure 7 illustrates typical voltage waveforms.

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15.6==

(choose 18 nF)

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Philips Semiconductors Product speciﬁcation

B B

BBBBBBBBBBBB

B B B B

B B B B B

B B B

B B B B

B B

Brushless DC motor drive circuit TDA5142T

BBBB

BBBB B B

B B

BBBB

BBBBBBBBBBB BBBBBBBBBBB

Fig.6 Typical application of the TDA5142T as a scanner driver, with use of OTA.

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

Fig.7 CAP-CD and CAP-DC typical voltage waveforms in normal running mode.

THE TIMING CAPACITOR (CAP-TI) Capacitor CAP-TI is used for timing the successive steps

within one commutation period; these steps include some internal delays.

The most important function is the watchdog time in which the motor EMF has to recover from a negative diode-pulse back to a positive EMF voltage (or vice versa). A watchdog timer is a guarding function that only becomes active when the expected event does not occur within a predetermined time.

The EMF usually recovers within a short time if the motor is running normally (<<ms). However, if the motor is motionless or rotating in the reverse direction, then the time can be longer (>>ms).

A watchdog time must be chosen so that it is long enough for a motor without EMF (still) and eddy currents that may stretch the voltage in a motor winding; however, it must be short enough to detect reverse rotation. If the watchdog

time is made too long, then the motor may run in the wrong direction (with little torque).

The capacitor is charged, with a current of 57 µA, from

0.2 to 0.3 V. Above this level it is charged, with a current of 5 µA, up to 2.2 V only if the selected motor EMF remains in the wrong polarity (watchdog function). At the end, or, if the motor voltage becomes positive, the capacitor is discharged with a current of 28 µA. The watchdog time is the time taken to charge the capacitor, with a current of 5 µA, from 0.3 to 2.2 V.

To ensure that the internal delays are covered CAP-TI must have a minimum value of 2 nF. For the watchdog function a value for CAP-TI of 10 nF is recommended.

To ensure a good start-up and commutation, care must be taken that no oscillations occur at the trailing edge of the flyback pulse. Snubber networks at the outputs should be critically damped.

Typical voltage waveforms are illustrated by Fig.8.

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

If the chosen value of CAP-TI is too small oscillations can occur in certain positions of a blocked rotor. If the chosen value is too large, then it is possible that the motor may run in the reverse direction (synchronously with little torque).

Fig.8 Typical CAP-TI and V

voltage waveforms in normal running mode.

MOT1

Other design aspects

There are other design aspects concerning the application of the TDA5142T besides the commutation function. They are:

• Generation of the tacho signal FG

• General purpose operational transconductance

amplifier (OTA)

• Possibilities of motor control

• Brake function

• Reliability.

SIGNAL

FG The FG signal is generated in the TDA5142T by using the

zero-crossing of the motor EMF from the three motor windings and the commutation signal.

Output FG switches from HIGH-to-LOW on all zero crossings and from LOW-to-HIGH on all commutations. Output FG can source typically 75 µA and sink more than 3 mA.

Example: a 3-phase motor with 6 magnetic pole-pairs at 1500 rpm and with a full-wave drive has a commutation frequency of 25 × 6 × 6 = 900 Hz, and generates a tacho signal of 900 Hz.

HE OPERATIONAL TRANSCONDUCTANCE AMPLIFIER (OTA)

T The OTA is an uncommitted amplifier with a high output

current (40 mA) that can be used as a control amplifier. The common mode input range includes ground (GND) and rises to VP− 1.7 V. The high sink current enables the OTA to drive a power transistor directly in an analog control amplifier.

Although the gain is not extremely high (0.3 S), care must be taken with the stability of the circuit if the OTA is used as a linear amplifier as no frequency compensation has been provided.

The convention for the inputs (inverting or not) is the same as for a normal operational amplifier: with a resistor (as load) connected from the output (AMP OUT) to the positive supply, a positive-going voltage is found when the non-inverting input (+AMP IN) is positive with respect to the inverting input (−AMP IN). Confusion is possible because a ‘plus’ input causes less current, and so a positive voltage.

OTOR CONTROL

M DC motors can be controlled in an analog manner using

the OTA. For the analog control an external transistor is required.

The OTA can supply the base current for this transistor and act as a control amplifier (see Fig.6).

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

BRAKE FUNCTION

• If the voltage on pin 8 is <2.3 V the motor brakes; in this condition the external outputs are driven to a HIGH voltage level.

• If pin 8 is floating or the voltage is >2.7 V the motor runs normally.

ELIABILITY

It is necessary to protect high current circuits and the output stages are protected in two ways:

• Current limiting of the ‘lower’ output transistors. The ‘upper’ output transistors use the same base current as the conducting ‘lower’ transistor (+15%). This means that the current to and from the output stages is limited.

• Thermal protection of the six output transistors is achieved in such a way that the transistors are switched off when the local temperature becomes too high.

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

PACKAGE OUTLINE

handbook, full pagewidth

pin 1 index

112

0.9

0.4

(4x)

15.6

15.2

1.27

0.49

0.36

0.1 S

1324

0.25 M

(24x)

2.45

2.25

0.3

0.1

10.65

10.00

detail A

7.6

7.4

1.1

0.5

1.1

1.0

0.32

0.23

0 to 8

MBC235 - 1

2.65

2.35

Dimensions in mm.

Fig.9 Plastic small outline package; 24 leads; large body (SOT137-1; SO24L).

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Philips Semiconductors Product speciﬁcation

Brushless DC motor drive circuit TDA5142T

SOLDERING Plastic small-outline packages

YWAVE

B During placement and before soldering, the component

must be fixed with a droplet of adhesive. After curing the adhesive, the component can be soldered. The adhesive can be applied by screen printing, pin transfer or syringe dispensing.

Maximum permissible solder temperature is 260 °C, and maximum duration of package immersion in solder bath is 10 s, if allowed to cool to less than 150 °C within 6 s. Typical dwell time is 4 s at 250 °C.

A modified wave soldering technique is recommended using two solder waves (dual-wave), in which a turbulent wave with high upward pressure is followed by a smooth laminar wave. Using a mildly-activated flux eliminates the need for removal of corrosive residues in most applications.

Y SOLDER PASTE REFLOW

B Reflow soldering requires the solder paste (a suspension

of fine solder particles, flux and binding agent) to be

applied to the substrate by screen printing, stencilling or pressure-syringe dispensing before device placement.

Several techniques exist for reflowing; for example, thermal conduction by heated belt, infrared, and vapour-phase reflow. Dwell times vary between 50 and 300 s according to method. Typical reflow temperatures range from 215 to 250 °C.

Preheating is necessary to dry the paste and evaporate the binding agent. Preheating duration: 45 min at 45 °C.

EPAIRING SOLDERED JOINTS (BY HAND-HELD SOLDERING

IRON OR PULSE

-HEATED SOLDER TOOL)

Fix the component by first soldering two, diagonally opposite, end pins. Apply the heating tool to the flat part of the pin only. Contact time must be limited to 10 s at up to 300 °C. When using proper tools, all other pins can be soldered in one operation within 2 to 5 s at between 270 and 320 °C. (Pulse-heated soldering is not recommended for SO packages.)

For pulse-heated solder tool (resistance) soldering of VSO packages, solder is applied to the substrate by dipping or by an extra thick tin/lead plating before package placement.

DEFINITIONS

Data sheet status

Objective speciﬁcation This data sheet contains target or goal speciﬁcations for product development. Preliminary speciﬁcation This data sheet contains preliminary data; supplementary data may be published later. Product speciﬁcation This data sheet contains ﬁnal product speciﬁcations.

Limiting values

Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the speciﬁcation is not implied. Exposure to limiting values for extended periods may affect device reliability.

Application information

Where application information is given, it is advisory and does not form part of the speciﬁcation.

LIFE SUPPORT APPLICATIONS

These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such improper use or sale.

June 1994 18