L6234 three phase motor driver - S · PDF fileback for motor current control. ... An evaluation of the power dissipation of the IC driving a three phase motor in a chopping current

INTRODUCTION

The L6234 is a DMOSs triple half-bridge driver with input supply voltage up 52V and output current of5A. It can be used in a very wide range of applications. It has been realized in Multipower BCD60II technology which allows the combination of isolated DMOStransistors with CMOS and Bipolar circuits on the same chip. It is available in Power DIP 20 (16+2+2)and in Power SO 20 packages.All the inputs are TTL/CMOS compatible and each half bridge can be driven by its own dedicated inputand enable. The DMOS structure has an intrinsic free wheeling body diode so the use of external diodes, which arenecessary in the bipolar configuration, can be avoided. The DMOS structure allows a very low quiescentcurrent of 6.5 mA typ. at Vs=42V , irrespective of the load.

DEVICE DESCRIPTIONThe device is composed of three channels. Each channel is composed of a half bridge with two powerDMOS switches ( typ. Rdson of 300mW @ 25°C) and intrinsic free wheeling diodes. Each channel in-cludes two TTL/CMOS and uP compatible comparators, and a logic block to interface the inputs with thedrivers. The device includes an internal bandgap reference of 1.22V, a 10V voltage reference to supplythe internal circuitry of the device, a central charge pump to drive the upper DMOS switch, thermal shut-down protection and an internal hysteretic function which turns off the device when the junction tempera-ture exceeds approximately 160 °C. Hysteresys is about 20 °C.

April 2001

®

AN1088APPLICATION NOTE

L6234 THREE PHASE MOTOR DRIVERby Domenico Arrigo

CHARGEPUMP

VREF10V

C310nF

C51µF

VREFVCP

C4 220nF

Vs C2100nF

C1100µF

THERMALPROTECTION

T1

T2

T3

T4

T5

T6

VBOOT

D21N4148

OUT1

OUT2

SENSE1

OUT3

SENSE2

IN1

EN1

IN2

EN2

IN3

EN3

D98IN940A

RSENSEGND

D11N4148

Vs

BRUSHLESSMOTOR

WINDINGS

Vs

Figure 1. L6234 Block Diagram

1/14

PIN DESCRIPTION.

Vs ( INPUT SUPPLY VOLTAGE PINS).

These are the two input supply voltage pins. The unregulatedinput DC voltage can range from 7V to 52V.With inductive loads the recommended operating maximumsupply voltage is 42V to prevent overvoltage applied to theDMosfets. In fact considering a full bridge configuration (seefig. 2), when the bridge is switched off (ENABLE CHOPPING)the current recirculation produces a negative voltage to thesource of the lower DMOS switches (point A). In this condi-tion the drain-source voltage of T1 and T4 is VS + VF + Vsense .Dinamically VF can be same Volts depending on the currentslope, dI/dt, and also Vsense, depending on the parasitic in-ductance and current slope can be some Volts. So the drain-source voltage of T1 and T4 DMOS switches can reach morethan 10V over the VS voltage. The input capacitors C1 and C2 are chosen in order to reduce overvoltagedue to current decay and to parasitic inductance. For this reason C2 has to be placed as closed as pos-sible to VS and GND pins.The device can sustain a 4A DC input current for each of the two Vs pins, in accordance with thepower dissipation.

OUT1, OUT2, OUT3 (OUTPUTS). These are the output pinsthat correspond to the mid point of each half bridge. They aredesigned to sustain a DC current of 4A.

SENSE1, SENSE2.SENSE1 is the common source of the lower DMOS of the halfbridge 1 and 2. SENSE2 is the source of the lower DMOS of the half bridge3. Each of these pins can handle a current of 5A. A resistance, Rsense, connected to these pins provides feed-back for motor current control.Care must be taken with the negative voltage applied to thesepins : negative DC voltage lower than -1V could damage thedevice. For duration lower than 300ns the device can sustainpulsed negative voltage up to -4V. For example, if enable chopping current control method isused, negative voltage pulses appear to these pins, due to thecurrent recirculation through the sensing resistor.

Vref ( Voltage Reference).This is the internal 10V voltage reference pin to bias the logicand the low voltage circuitry of the device. A 1µF electrolytic ca-pacitor connected from this pin to GND ensures the stability of theDMOS drive circuit. This pin can be externally loaded up to 5mA .Figure 3 and 4 show the typical behavior of the Vref pin.

Vcp ( CHARGE PUMP ).This is the internal oscillator output pin for the charge pump.The oscillator supplied by the 10V Voltage Referenceswitches from GND to 10V with a typical frequency of

-50 -25 0 25 50 75 100 125 1500

1

2

3

4

5

6

7

8

9

10

11

Tj [°C]

Vref [V]

Vs = 52V

Vs = 24V

Vs = 7V

Vs = 10V

Figure 3. Reference Voltage vs.Junction Temperature.

0 10 20 30 40 500

2

4

6

8

10

12

Vs [V]

Vref [V]

Tj = 25°C

Figure 4. Reference Voltage vs.Supply Voltage.

L

ON/OFF

ON/OFFT1

C

T3

T2 T4

B

A

(VS+VF)

-VSENSE

-VF

VS

VF

ON

OFF

Rsense

D98IN938A

S

Figure 2.

AN1088 APPLICATION NOTE

2/14

1.2MHz (see fig 4). When the oscillator output is at ground , C3 is charged by Vs through D1. When itrises to 10V, D1 is reverse biased and the charge flows from C3 to C4 through D2, so the Vboot pin af-ter a few cycles reaches the maximum voltage of Vs + 10V - VD1- VD2.

Vboot ( BOOTSTRAP).This is the input bootstrap pin which gives the overvoltage necessary to drive all the upper DMOS of thethree half bridges (see fig 5).

LOGIC INPUTS PINS.

EN1, EN2, EN3 (ENABLES). These pins are TTL/CMOS and µP compatible. Each half bridge can be enabled by its own dedicatedpin with a logic HIGH. The logic LOW on these pins switches off the related half bridge (see Fig. 6). Themaximum switching frequency is 50kHz.

IN1, IN2, IN3 (INPUTS).These pins are TTL/CMOS and µP compatible. They allow switching on the upper DMOS ( INPUT athigh logic level) or the lower Dmos (INPUT at low logic level) in each half bridge (see Fig. 6).

10nFVCP

1N4148

0.22µF

VBOOT

1N4148

CHARGE

PUMPVref10V

0.1µF

Vs

100µF

HIGH SIDE DRIVER

Vs+Vref-VD1-VD2

Vref

f=1.2 MHz

Vs+Vref-VD1

Vs-VD1f=1.2 MHz

D1

D2

C3

C4

C2 C1

OUT

Vs

SENSE

Figure 5. Charge Pump Circuit.

UPPER DMOS

LOWER DMOS

DMOS ON

DMOS OFF

DMOS ON

time

time

DMOS OFF

ENABLEhigh level

low level

time

DMOS OFF

INPUT

time

high level

low level low level

high level

high level

DMOS OFF

low level

DMOS OFF

DMOS OFF

Figure 6. Control logic for each half bridge.

tdelay

300ns

tdelay300ns

INPUT PIN

UPPER DMOS

LOWER DMOS

high level

low level

DMOS ON

DMOS OFF

DMOS ON

DMOS OFF

time

time

time

DMOS OFF

DMOS ON

low level

Figure 7. Cross Conduction Protection.


3/14

Cross conduction protection (see Fig. 7) avoids simultaneously turning on both the upper and lowerDMOS of each half bridge. There is a fixed delay time of 300ns between the turn on and the turn off ofthe two DMOS switches in each half bridge. The switching operating frequency is up 50kHz. High com-mutation frequency permits the reduction of ripple of the output current but increases the device’s powerdissipation, however low commutation frequency causes high ripple of the output current. The switchingfrequency should be higher than 16kHz to avoid acoustic noises.The sink current at the INPUTS and ENABLES pins is approximately 30µA if the voltage to these pins isat least 1V less than the Vref voltage (see Fig. 3 and Fig. 4). To avoid overload of the logic INPUTS andENABLES , voltage should be applied to Vs prior to the logic signal inputs.

POWER DISSIPATIONAn evaluation of the power dissipation of the IC driving a three phase motor in a chopping current con-trol application follows.With a simplified approach it can be distinguished three periods (see Fig. 8) :

Rise Time, Tr, period.This is the rise time period, Tr, in which the cur-rent switches from one winding to another. In thistime a DMOS is switched on and the current in-creases up to the peak value Ipk with the law i(t)= (Ipk/Tr) t. The energy lost for the rise time inthe period T is :

Erise = ∫ 0

TrRdson ⋅ i2(t)dt = Rdson ⋅ I2pk ⋅ Tr

3 Fall Time,Tf, period.When the current switches from one winding toanother, there is a fall time in which the currentthat flows in the intrisic diode of the DMOS de-creases from Ipk to zero. If VD is the voltage fallof the diode, the energy lost is :

Efall = ∫ 0

tfVD(t) ⋅ i(t)dt

TloadDuring this time the current that flows in the winding is limited by the chopping current control. The en-ergy dissipated due to the ON resistance of the DMOS is :

Eload = Rdson ⋅ (Irms)2 ⋅ TloadIn the formula, Irms is the RMS load current, given by :

Irms = √(Iload)2 +

Ipk − Ival√3

2

and Iload is the average load current.When the switch is ON, the energy dissipated due to the commutation of the chopping current control inthe DMOS can be assumed to be:

Eon = Vs ⋅ Ival ⋅ tcom2

where tcom is the commutation time of the DMOS switch.

Trise TfallTload

Tchop

Ipk

Ival

Iload

Figure 8.


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When the switch is OFF : Eoff = Vs ⋅ Ipk ⋅ tcom

2

The energy lost by commutation in a chopping period, given by Eon + Eoff, is :

Ecom = Vs ⋅ Iload ⋅ tcom

The energy lost by commutation during the Tload time is given by :Ecom = Vs ⋅ Iload ⋅ tcom ⋅ Tload ⋅ fchop

Quiescent Power Dissipation, Pq.The power dissipation due to the quiescent current is Pq = Vs ⋅ Iq , in which Iq is the quiescent currentat the chopping frequency, fchop = 1/Tchop.

Total Power Dissipation .Let’s evaluate the power dissipation of the device driving a three phase brushless motor in chopping cur-rent control. In the driving sequence only one upper DMOS and a lower one are on at the same time(see fig. 9 and 10). The total power dissipation is given by :

Ptot = 2 ⋅ (Erise + Efall + Eload + Ecom)

T + Pq

Figure 11 shows the total power dissipation, Pd, of the L6234 driving a three phase brushless motor ininput chopping current control at different chopping frequency.

EVALUATION BOARD. The L6234 Power SO20 board has been realized to evaluate the device driving, in closed loop control, athree phase brushless motor with open collector Hall effect sensors.

ILOAD

I1B

I1A

I2B

half bridge 1 half bridge 2

OUT1 OUT2

I1B I2B

I1A

ILOAD

Vs

ON/OFF

OFF/ON ON

OFF

_PHASE 12 CHOPPING INPUT

IOFF

Figure 9. Input chopping current circulation.


5/14

The device soldered on the copper heat dissipatingarea on the board ,without any additional heat sink,can sustain a DC load current of 2.3 A at Tamb ofapproximately 40 °C. The board provides a closed loop speed and torquecontrol, with a constant TOFF chopping current con-trol method. It allows the user to change the direc-tion and brake the motor.

Constant t OFF Chopping Current Control.When the current through the motor exceeds thethreshold, fixed by the ratio between the controlvoltage Vcontrol and the sensing resistor, Rsense,an error signal is generated, the output of theLM393 comparator switches to ground. This state ismaintained by the monostable (M74HC123) for aconstant delay time ( tOFF ) generating a PWM sig-nal that achieves the chopping current control. ThePWM signal is used for chopping the INPUT pat-tern. During the toff in chopping current control, thecurrent flows in the low side loop ( see fig. 9 ) and does not flow through the sensing resistor. The tOFF value can be set by the R9 and C11 to values shown in the table 1.A suitable value of toff for the majority of applications is 30µs. The larger the tOFF, the higher is the cur-rent ripple. If the tOFF is too large the ripple current becomes excessive . On the other hand if the tOFF istoo small the winding current cannot decrease under the threshold and current regulation is not guaran-teed.

IOUT1

IOUT2

IOUT3

T

OUT3

L6234

OUT2

OUT1

BRUSHLESS MOTOR

Figure 10. Three Phase Brushless motor control sequence.

0 1 2 3 4 50

ILOAD [A]

Pd [W]

DC

fchop=30kHz

fchop=50kHz15

10

5

INPUT CHOPPINGVs=36VL=2mHT=2msTj=100C

Figure 11. L6234 Power Dissipation in ThreePhase Brushless Motor Control.


6/14

Torque & Speed Closed Loop Control.The motor’s rotational speed is determined by the frequency of the Hall effect signals. The speed controlloop has been achieved by comparing this frequency with a frequency of a reference oscillator (see fig.14) that corresponds to a desired speed limit.

3OUT3

L6234

C1 100uF 60V

EN3

IN3

IN2

IN1

EN1

EN2

OUT2

OUT1

VbootVcpVs

79 12 17 18

6

5

15

4

14

8

13

D1 D2C4

C3 10nF

C2 220nF100nF

1N4148 1N4148

POWER SO20

1 2

GND

+5V

Vref

10 11 20 16 19

C51uF

R10 10K each

IN2

IN1

IN3

EN3

EN2

EN1

SENSE

R1 R2 R3 R4

REFERENCESPEED

CONSTANT toff CHOPPING CURRENT CONTROL

Vsense

Vcontrol TORQUE &SPEED

CONTROL

PWM

BRUSHLESS MOTOR

HALL EFFECT

SENSORS

CONTROL LOGIC

HALL EFFECT SIGNALS

BRAKEDIR

PWM

Hall effect signal

C6 220nF

1

2IN

3OUT

L7805

GND10uF C7

Z1 18V

R5 10k

T1+5V

J7

Reference Speed

Vs=8V to 42

1Ω 1Ω 1Ω 1Ω

Figure 12. Application board Schematic Circuit.

M74HC123monostable

+5V

+5V

C11330pF

R9

100nFC10 2 316

415 14 8

1

100k

R11

10k

Vcontrol

PWM

+5V

100nF

LM393

R7 11 k

R81K

C8 470pF

R6 1K2 Vsense

1

+5V

8

34+

-

C9

_Q

A

B

+5V

J1

Figure 13. Constant toff current control.

toff R9 C11

20µs 100k 270pF

30µs 100k 330pF

45µs 100k 560pF

70µs 100k 1nF

Table 1. toff selection

PHASE/FREQUENCYDETECTOR

HALLSENSORS

COMPENSATIONNETWORK

PWMVcontrol

Amp. MOTOR

REFERENCE

FEEDBACK

D01IN1209

Figure 14. PLL Motor Control.


7/14

When the hall effect signal fre-quency is lower than the referencefrequency, the control voltage ismaintained to a value that sets themotor current limit and therefore thetorque control limit. The peak cur-rent limit is given by Ipeak = Vcon-trol/Rsense.When the frequency from the HallEffect sensors exceeds the refer-ence frequency and an error signalis generated by the PLL (see Fig.14). An LM358 comparator, a loopamplifier and an auxiliary OP-AMPensure the right gain and filtering toguarantee the stability (see fig.16).The error signal causes Vcontroldecrease to a value that sets thePWM chopping current control in or-der to reduce the torque and setthe desired speed. The motorspeed is regulated to within ± 0.02% of the desired speed.

Control Logic Circuit.The logic sequence to the motor isgenerated by a GAL16V8, whichdecodes the Hall Effect signals andgenerates the INPUT and ENABLEpattern shown in Fig. 18.The brake function is obtained bysetting the input pattern to logic lowand thus turning on the lowerDMOS switches of the enabled half-bridges. The PWM signal is used for chop-ping the INPUT pattern.

The control logic circuit decodesHall effect sensors having differentphasing.With the DIR jumper opened theapplication achieves forward rota-tion for motors having 60° and 120°Hall Effect sensor electrical phasingand the reverse rotation for motorshaving 300° and 240° Hall Effectsensor phasing.Connecting the DIR jumper toground sets the reverse rotation formotors having 60° and 120° Hallsensors phasing and the forwardrotation for motors having 300° and240° Hall sensor phasing.The SW2 switch performs the start-stop function.

Reference Speed

NE555

100nFC21

4 7

1

+5V

100nF

2

R27

16K

C20

R2636K

5

3 8

6

100nFC19

Figure 15. Oscillator for Reference Speed.

R16

270K

3 1

GND

+5V

7

9

12

6

5

15

13

14

8 1011

2

4

16

C15100nF

BAT47

HALL1 (Speed feedback)

+5V+VIN

100nFC14C13

1uF

3635

+5V

Vcontrol

+5V

5K

R1447K

R1347K

R20R1547K

R18

33K

C16220nF

C1747nF

R1991K R21

91K

R17

10MLM358

+5V

R1247K

21

C12100nF 8

3

4

+-

P21K

P1

GND

Reference Speed

TP8

Phase/ FrequencyDetector

2.5VLoopAmplifier

Aux.OP-AMP

Output

Figure 16. Phase Locked Loop and filtering.

100nF

C18

2

3GAL 16V8

4

191

610

5

20

PWM+5V

PWM

BRAKE

DIR

HALL1

HALL2

HALL3

EN1

EN2

EN3

IN1

IN2

IN3

16

15

14

18

17

BRAKE DIR

GND

+5V

MOTOR HALL EFFECT SIGNALS

DIRECTION CHANGE

DIR =0 GND : BACK ROTATION DIR = 5V : FORWARD ROTATION

BRAKE FUNCTION

BRAKE = GND : BRAKE BRAKE = 5V : GO

IN2

IN1

IN3

EN3

EN2

EN17

+5V

R2510k

R2610k

R2210k

R2310k

R2410k

R2910k

SW1J1

SW2

Figure 17. Control Logic Circuit.


8/14

0˚

HALL1

D98IN912

HALL2

HALL3

SENSORSIGNALS

EN1

EN2

EN3

ENABLE

IN1

IN2

IN3

FORWARDROTATION

IN1

IN2

IN3

REVERSEROTATION

IOUT1

IOUT2

IOUT3

MOTORDRIVE

CURRENTIN

FORWARDROTATION

NO PWM PWM CONSTANT tOFF

ELECTRICAL DEGREES

0

0

0

360˚

Figure 17.


9/14

Layout Considerations.Special attention must be taken to avoid overvoltages at Vs and additional negative voltages to theSENSE pins and noise due to distributed inductance. Thus the input capacitor must be connected closeto the Vs pins with symmetrical paths. The paths between the SENSE pins and the input capacitorground have to be minimized and symmetrical . The sensing resistors must be non-inductive. The de-vice GND has to be connected with a separate path to the input capacitor ground.

Figure 20. Component side.

Figure 19. Application Board Layout.


10/14

APPLICATION IDEAS.The L6234 can be used in many different applications. Typical examples are a half bridge driver usingone channel and a full bridge driver using two channels. In addition, the bridges can be paralleled to re-duce the RDSon and the device dissipation.The paralleled configuration can also be used to increase output current capability. Channel 1 can beparalleled with Channel 3 or Channel 2 can be paralleled with Channel 3. Channel 1 should not be paral-leled with Channel 2 because the sources of their low side DMOSs are connected to the same SENSE1pin .Application ideas for the L6234 follow.

Figure 21. Copper side.

CONTROL LOGIC

L6506+5V

100nF

QR

S

QRS

OSC+5V

RSENSE

OUT3

L6234 EN3

EN1

EN2

Vs

100uF

1N4148 1N4148

IN3

IN2

IN1

OUT2

OUT1VbootVcpVs

10nF 220nF

100nF

POWER SO20

GND Vref

SENSE2

1uF

Vsense

Constant frequency Current Control

Vcontrol

+5V

IN1

IN2

IN3

Reset

EN3

EN1

EN2

SENSE1

Rx

Cx

1 Fchop= __________ 0.69 Rx Cx

for Rx>10kOhm

Figure 22. Constant frequency current control


11/14

Low Cost Application with Speed and Torque Control Loops.

A low cost solution to obtain a complete three phase brushless motor control application with speed andtorque closed control loop is shown in Fig. 23. This simple low cost solution is useful when high dynamicperformances and accuracy of the speed loop are not required.

The current regulation limit, which determines the torque , is given by Vcontrol/Rsense. The constanttoff of the PWM is fixed by Rx2 and Cx2. The speed loop is realised using a Hall effect signal, whose frequency is proportional to the motorspeed. At each positive transition of the Hall effect sensors the monostable maintains the pulse for aconstant time , Ton, with a fixed amplitude, V5. The average value of this signal is proportional to the fre-quency of the Hall effect signal and the motor speed . An OP-AMP configured as an integrator , filtersthis signal and compares it with a reference voltage, Vref, which sets the speed . The generated errorsignal is the control voltage, Vcontrol, of the currrent loop. Therefore the current loop modifies the pro-duced torque in order to regulate the speed at the desired value.The values of Cf and R2 should be chosen to obtain a nearly ripple free op-amp output, even at low mo-tor speed. This constrain limits the system bandwidth and so limits the response time of the loop. The regulated speed, for a rotor with n pairs of permanent magnetic poles , is given by :

ωm =

1 +

R1R2

V5 ⋅ Ton ⋅ n + 1

KG

⋅ Vref ⋅ 60 [RPM]

with KG = R4

R3 + R4 ⋅ Kt ⋅ 1

Rsense ⋅ 1

B ⋅ R2

R1

in which Kt, expressed in [Nm/A] , is the Motor Torque constant and B, expressed in [Nms], is the TotalViscous Friction.In most cases 1/KG can be neglected.

HALLEFFECT

SENSORS

HALLEFFECTSIGNALS

VS

+5V

1/4TSM221

Q

V5=+5V

PWM

OUT1

OUT2

OUT3

BRUSHLESS MOTOR

SPEED LOOP

L6234POWER SO20

CONTROLLOGIC

IN1

IN2

IN3

EN1

EN2

EN3

17 18

6

7

4

14

8

3

13

12

1Q13

1B

HALL EFFECT SIGNAL

27

17

1

4

11

6 VSENSE

2

3

51110

1,10,11,20

-

+

-

+

16 2 19

5

15

GND SENSE

RSENSE0.3W

C1 200nF

R2 1MR1 100K Ton

1/fe

Vm

V5

R3 4KVCONTROL

1/4TSM221

R41K

V5=+5V

Vref

+5VRx2

Cx2

9 12

6 163

15 1 14 8

+5VRx1

100K Cx1

A

(ReferenceSpeed Voltage)

1/2M74HC123

MONOSTABLE

1/2M74HC123

MONOSTABLE

D01IN1210

Figure 23. Complete three phase brushless motor application with speed and torque control.


12/14

The Ton values, given by KCx1Rx1, must be less than the period of the Hall effect electrical signal atthe desired motor speed , so Ton must meet the requirement of 1.1 :

( 1.1 ) Ton < 60

n ⋅ ωm For the motor and the load used in this application, which have the following parameters :

Jt = 10-4 [Kg ⋅ m2] (Motor plus Load Inertia Moment); Kt = 10-2 [Nm/A] ; B = 10-5 [Nms] n=4 ; R1=100k +/- 10% [kΩ] ; R2=1M ±1[kW] ; Cf=220n [F]

A regulated speed of 6000RPM can be obtained with an accuracy of around +/-3%, considering Ton ac-curacy of +/-1% , the V5 and Vref mismatch of +/-1% .If the speed is 6000RPM, there are 100 rotor revolution for second, with n=4, the Hall effect frequency is 400Hz. Therefore Ton has to be lower than 2.5ms (according to equation 1.1).The phase margin is about 45° and the response time of the speed loop for a speed step variation isaround 200ms .

6X6 BRUSHLESS APPLICATION

Vcontrol

Constant Toff PWM Current Control. Two M74HC124 plus an LM339

THREE PHASEBRUSHLESS MOTOR

IN1B

IN1A

IN2A

EN2

EN1OUT3

L6234

EN3

EN1EN2

IN3IN2IN1

OUT2

OUT1VbootVcpVs

Vs

100uF 1N4148 1N4148

10nF 220nF100nF

GND VrefSENSE1

1uF

SENSE2

IN3B

IN3A

IN2BEN3

OUT3

L6234

EN3

EN1EN2

IN3

IN2IN1

OUT2

OUT1VbootVcpVs

Vs

100uF

1N4148 1N4148

10nF

220nF100nF

GND VrefSENSE1

1uF

SENSE2

M74HC123monostable

+5V

100nF 2 316

415

14 8

1

+5V

+5V 100nFLM339

470pF

1K

1

+5V

8

+-

_Q

A

B

4

Comparator & monostable



CONTROL LOGIC

Vsense1

Vsense2

Vsense3

PWM1

PWM2

PWM3

OUT1A

OUT1B

OUT2A

OUT2B

OUT3B

OUT3A

SPEED AND POSITION FEEDBACK

Figure 24. 6x6 Three Phase Brushlees Application Circuit


13/14

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequencesof use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license isgranted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication aresubject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics productsare not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.

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Documents

L6234 three phase motor driver - S · PDF fileback for motor current control. ... An evaluation of the power dissipation of the IC driving a three phase motor in a chopping current