OM9373SPP - International Rectifier

11/21/03

www.irf.com 1

FULL-FEATURED POWER MODULE OM9373SP

FOR DIRECT DRIVE OF

3-PHASE BRUSHLESS DC MOTOR

F-43 / MP3-43L Packages

Features:

nFully Integrated 3-Phase Brushless DC Motor

Control Subsystem includes Power Stage,

Non-Isolated Driver Stage and Controller Stage

nMOSFET Output Stage

n25A Average Phase Current with 80V

Maximum Bus Voltage

n Internal Precision Current Sense Resistor

(6W Max. Dissipation)

nSpeed and Direction Control of Motor

nBrake Input for Dynamic Braking of Motor

nOvervoltage/Coast Input for Shutdown of

All Power Switches

nSoft Start for Safe Motor Starting

nUnique Her metic or Plastic Ring Frame Power

Flatpacks

Hermetic (3.10” X 2.10” X 0.385”)

Plastic Ring Frame (4.13” X 2.00” X 0.49”)

Applications:

nFans and Pumps

nHoists

nActuator Systems

The OM9373 is one of a series of versatile, integrated

three-phase brushless DC motor controller/driver

subsystems housed in a 43 pin power flatpack. The

OM9373 is best used as a two quadrant speed

controller for controlling/driving fans, pumps, and

motors in applications which require small size.

Many integral control features provide the user much

flexibility in adapting the OM9373 to specific system

requirements.

MP3-43L

Description:

F-43

The small size of the complete subsystem is ideal for

aerospace, military , and high-end industrial applications.

Two package types provide a broad range of cost

and screening options to fit any application.

25A Push-Pull

3-Phase Brushless DC Motor

Controller / Driver Module

in a P o wer Flatpac k

OM9373SF

OM9373

PD- 94705

OM9373

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* TCASE = 25°C

* * TCASE = 25°C, Maximum pulse width = 10 mS

Note 1: Logic Inputs: Direction, Hall Inputs (H1--- H3) Overvoltage - Coast, Speed, and Quad Select.

Note 2: The inter nal 5mΩ current sense resistor is limited to 6 Wdc power disipation. Other values are avaliable.

Please contact International Rectifier for more information.

Absolute Maximum Ratings

Parameter Symbol Value Units

Motor Supply Voltage Vm80

Pe a k Motor Supply Voltage Vm pk 100

Average Phase Output Current Io25 A*

Peak P hase Output Current Iom 50 Apeak **

Co ntro l Supp ly Voltage Vcc +18

Logic I nput Voltag e ( Note 1) -0 . 3 to +8 . 0

Reference Source Current -30 mA

Error Amplifier Input Voltage Range ( EA1+ / EA1-) -0.3 t o +10 V

Error Amplifi er Output Current ±8 mA

S pare Am pli f ier I nput V o l tag e ( EA2+ / EA2-) -0 . 3 to +1 0 V

Spare Amplifier Out put Current ±8 mA

Cur rent Sen se Am pli fier In put Vo lt age (ISH / ISL) -0.3 to +6.0 V

Current Sense Amplifier Output Current

Tachometer O utpu t C ur r ent

PWM Input Voltage -0.3 to +6.0 V

Operating Junction Temperature -55 to 150

S t o r age Te m pe rat ur e Ra nge -6 5 t o 150 ° C

Lead Sol dering Te m perature , 10 s ma ximum, 0.125" fro m case 300

Package Isolation Voltage 600 Vrms

Pow er Swi tch Junct io n- t o- C ase Thermal Resista nce RθJC 0.35 °C/W

±10 mA

Recommended Operating Conditions ( Tcase = 25° C )

Parameter Symbol Value Units

Motor Po wer Supp ly Vo ltag e Vm+48 V

Average Phase Output Current

With Internal Current Sense Resistor ( Note2 ) Io25 A

Eac h Power Swi tch

Con tr o l Su pply V o lt age Vcc 15+10%

Logic Low Inpu t Vo ltag e (m ax imum ) Vil 0.8 V

Logic High Input Voltage (minimum) Vih 2.0

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OM9373

Elect rical Char acteri sti cs

Parameter Symbol Test Conditions (Note 1) Min. Typ. Max. Units

Power Output Sect ion

Zero Gate Voltage Drain C urrent Idss Vds = 80Vdc, Vgs = 0V --250

µΑ

Drain-to-Source On-Resistance Rds(on) Id = 35A, Vgs = 10V ( Note 4 ) - - 0.024 Ohms

Gate Body Leakage Current Igssr Vgs = 20Vdc, Vds = 0V --100nA

Di o d e Forw ard Voltag e VfIS = 35A --0.9V

Di od e R ev e r s e Rec over y Ti m e trr IS = 25A , di /d t = -10 0A/µsec, VGS = 0V --200nS

Control Section

Co ntrol Su pp ly Curr en t Icc VCC over operat ing range --100mA

Control Turn-On Threshold 9.45 - -

Driver Turn-On Threshold 13 - -

Reference Section

Output Voltage 4.9 5.0 5.1

Output Voltage 4.7 5.0 5.3

Output Current Io - - 30 mA

Load Regulation ILOAD = 0mA to -20mA -40 -5.0 - mV

Short Circuit Current Isc TC over operat ing range 50 100 150 mA

Error / Sp a r e A mplifiers Section

EA1 / EA2 Inpu t Offset Cur rent Ios V(pin 2) = V(pin 4) = 0V, -30 -3.0 0

V(pin 3) = V(pin 6) = 0V

EA1 / EA2 In put Bias Current Iin V(pin 2) = V(pin 4) = 0V, -50 -45 0

V(pin 3) = V(pin 6) = 0V

In p ut Offset Vol tage Vos 0V < Vcommon-mode < 3.0V - - 7.0 mV

Amplifier Output Voltage Range - 0 - 6.0 V

PWM Comparator Section

P WM In pu t C urre nt Iin V (pi n 9) = 2. 5V 0 3 . 0 3 0 µΑ

Current-Sense Amplifier Section

IS H / IS L In pu t Curr e nt Iin V(pin 12) = V(pin 13) = 0V, -850 -320 0

In p ut Offset Curren t Ios V(pin 12) = V(pin 13) = 0V, - ±2.0 ±12

Peak Current Threshold Vol tage Vpk V(pin 12) = 0V, V(pin 13) Varied to 0.14 0.20 0.26

Over Current Threshold Voltage Voc Threshold 0.26 0.30 0.36 V

I SH / ISL In pu t V o lt age Ran ge - ( N ot e 2 ) -1 .0 - 2 .0

Amplifier Voltage Gain AVV(pin 12) = 0. 3V, V(pin 13) = 0.5V to 0. 7V 1.75 1.95 2.15 V/V

Amplifier Level Shift - V(pin 12) = V(pin 13) = 0.3V 2.4 2.5 2.65 V

µΑ

Vcc(+) TC over operating range V

Vref TC over operating range V

OM9373

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1. All parameters specified for Ta = 25°C, Vcc = 15Vdc, Rosc= 75KΩ (to Vref), Cosc = 1800pF, and all Phase Outputs unloaded (Ta-Tj).

All negative currents shown are sourced by (flow from) the pin under test.

2. Either ISH or ISL may be driven over the range shown.

3. Bold parameters tested over temperature range.

4. Pulse Test: Pulse Width £ 300 µSec,Duty Cycle £ 2%.

Specification Notes:

Elect rical Char acteri sti cs - Continue d

Parameter Symbol Test Conditions (Note 1) Min. Typ. Max. Units

Logic Input Section

H1, H2, H3 Low Volt ag e Thres h ol d Vil 0.8 1.0 1.2

H1, H2, H3 High Voltage Threshold Vih 1.6 1.9 2.0

H1, H2, H3 Input Current Iin TC over operating range, -400 -250 -120 µΑ

V ( pin 20 , 21, or 22) = 0Vdc

Quad Select / Direction Threshold Voltage Vth TC over operating range 0.8 1.4 2.0 V

Qua d Select Vo ltage Hysteresi s - 70 - mV

Direc tion Vo ltage Hy s t eres is - 0. 6 - V

Quad Se lect Input Current -30 50 150

Direct io n Input Current -30 -1 .0 30

Overvoltage / Coast Input Section

Ov er vol t age / Coast Inhi bit Th r e shol d V oltage 1.65 1.75 1.85

Ov er voltag e / C oast Restar t Thres h old Vo ltage TC over operating range 1.55 1.65 1.75 V

Overvolt age / Coast H yste r esi s Vol ta ge Vh0.05 0.10 0.15

Overvolt age / Coast R est ar t Inp ut Curr ent Iin -10 -1.0 0 µΑ

Soft-Start Section

Soft-Start Pull-Up Current IpV(pin 18) = 0V -16 -10 -5.0 µΑ

Sof t-S tart Disc h arge Current IdV(pin 1 8) = 2.5V 0.1 0.4 3. 0 mA

Soft-Start Reset Threshold Voltage Vth 0.1 0.2 0.3 V

Tachometer/Brake Section

Ta chometer Out put High Level Voh Tc over operat ing range 4.7 5.0 5.3

Ta chometer Out put Low Level Vol (pin15) 10KΩ to 2.5V --0.2

Ta chometer On-Tim e ton 85 100 140 µS

Tachometer O n- Tim e Variation - TC over operating range -0.1-%

Bra ke/Ta ch Timin g In put C ur r ent Iin V(pin 16) = 0V -4.0 -1.9 - mA

Brake/Tach Ti ming Threshold Voltage Vth TC over operating range 0.8 1.0 1.2

Voltage Hysteresi s Vh-0.09-

Speed Inpu t Thr eshold Volt age Vth TC over operating range 220 257 290 mV

Speed In put C ur r ent Iin -30 -5.0 30 µA

Oscillator Section

Oscillator Frequency

oMe asu r ed at pin 10 13.5 14. 8 2 0 KH z

VTC over operating range

Vth

lin µΑ

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OM9373

The OM9373 3-phase brushless DC motor controller/

driver is designed to drive fractional to integral

horsepower motors. To ensure proper operation, it is

necessary to ensure that the high-side bootstrap

capcitors are charged during initial start-up. However ,

the method(s) used to ensure this may be dependant

upon the application. For example, some applications

may only require that OV_COAST (pin 17) be

connected to ground, either via a hardwire connection

or via a s witch (Enable/Disable), before applying Vcc.

When Vcc is applied, the controller/driver is forced

into brake mode for approximately 200µs (all high-

side drivers are disabled and all low-side drivers are

enabled).

APPLICATIONS

Start-Up Conditions

Fig 1: Optional Start-Up Circuit

This may not be adequate for other applications;

while maintaining a constant speed command,(above

zero),the RC_BRAKE (pin 16) may have to be

momentarily connected to ground via a switch,

either manually or electronically (ref. Figure 1).

Note that with the component values shown in

Figure 1, RC_BRAKE is pulled for low for approximately

300ms after applying Vcc at pin 1.

OM9373

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Modes of Operation

Figures 2 and 3, shown on the following pages,

provides schematic representations of typical voltage-

mode and current -mode applications for the OM9373

controller/driver.

Figure 2 represents the implemenation of a typical

voltage-mode controller for velocity control. A voltage

or speed command is applied to the noninverting

input of the error amplifier which is configured as

voltage follower. The ouput of the error amplifier is

compared to a pulse width modulated ramp,and

since motor speed is nearly proportional to the

average phase output voltage, the average speed is

controlled via duty cycle control. If a speed feedback

loop is required, the tachometer output can be

connected to the inverting input of the error amplifier

via a loop compensation network.

Fig 2: Implementation of a Voltage -Mode Controller

C_FILT

232

4700pF

.1uF

3.24k

1.50k

.1uF

C_BUS +

10uF +

.1uF 10k

Vcc

VREF

OSCILLATOR

10 PWM_IN

9EA1_OUT

EA1+

EA1-

SOFT_START

I_SENSE

ISH

ISL

QUAD_SEL

DIRECTION

24 SPEED_IN

EA2_OUT

EA2+

EA2-

BRAKE

16 TACH_OUT

GROUND

V_MOTOR 43

PHASE_A_OUT 42

PHASE_A_OUT 41

SOURCE_A 40

SOURCE_A 39

V_MOTOR 38

PHASE_B_OUT 37

PHASE_B_OUT 36

SOURCE_B 35

SOURCE_B 34

V_MOTOR 33

PHASE_C_OUT 32

PHASE_C_OUT 31

N/C 30

SOURCE_C 29

MOTOR_RETURN 28

MOTOR_RETURN 27

H1_HALL_INPUT

22 H2_HALL_INPUT

21 H3_HALL_INPUT

CSH

CSL

OV_COAST

V_MOTOR

COMMAND

+15V

HALL SENSORS

FROM MOTOR HALL SENSORS

MOTOR

Figure 2 also shows the implementation of the

cycle-by-cycle current limit/overcurrent protection

feature of the OM9373. The load current is monitored

red via the controller’s inter nal sense resistor. The

current sense signal is filtered and fed into the current

rent sense amplifier where the absolute value of

ISH-ISL is multiplied by two and biased up by 2.5V

The output of the current sensor amplifier is compared to

a fixed reference, thus providing cycle-by-cycle

current limiting and/or overcurrent protection as

necessary. The typical peak current threshold (ISL-ISH)

is 0.2V; the typical over current threshold (ISH-ISL) is

0.3V.

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OM9373

Figure 3 represents the implementation of a typical

current-mode controller for torque control. The load

current is monitored via the controller’s internal sense

resistor. The current sense signal is filtered and fed

into the current sense amplifier where the absolute

value of ISH-ISL is multiplied by two and biased up by

2.5V. Besides the implementation of the cycle-by-

cycle current limit/overcurrent protection feature of the

OM9373 discussed in the preceding paragraph, the

output of the current sense amplifier is fed into the

error amplifier which is configured as a differential

amplifier . An error signal representing the difference

between the current command input and the value

of the amplified current sense signal is produced.

Then it is compared to a pulse width modulated

ramp and since torque is nearly proportional to the

average phase output current, the torque controlled

via duty cycle control.

C_BUS +C_FILT

232

4700pF

.1uF

.1uF10uF +

.26uF

43k

1800pF

3.24k

35.6k

10k.1uF

Vcc

VREF

OSCILLATOR

10 PWM_IN

9EA1_OUT

EA1+

EA1-

SOFT_START

I_SENSE

ISH

ISL

QUAD_SEL

DIRECTION

24 SPEED_IN

EA2_OUT

EA2+

EA2-

BRAKE

16 TACH_OUT

GROUND

V_MOTOR 43

PHASE_A_OUT 42

PHASE_A_OUT 41

SOURCE_A 40

SOURCE_A 39

V_MOTOR 38

PHASE_B_OUT 37

PHASE_B_OUT 36

SOURCE_B 35

SOURCE_B 34

V_MOTOR 33

PHASE_C_OUT 32

PHASE_C_OUT 31

N/C 30

SOURCE_C 29

MOTOR_RETURN 28

MOTOR_RETURN 27

H1_HALL_INPUT

22 H2_HALL_INPUT

21 H3_HALL_INPUT

CSH

CSL

OV_COAST

V_MOTOR

+15V

CURRENT_COMMAND

HALL SENSORS

FROM MOTOR HALL SENSORS

MOTOR

OFFSET

Fig 3: Implementation of a Current-Mode Controller

OM9373

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Simplified Block Diagram

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OM9373

Pin Descriptions / Functionality

VCC (Pin 1) -- The Vcc Supply input provides bias

voltage to all of the internal control electronics

within the OM9373, and should be connected to a

nominal +15Vdc power source. High frequency

bypass capacitors (10uF polarized in parallel with

0.1uF ceramic are recommended) should be connected

as close as possible to pin 1 and Ground (pin 19).

ERROR AMPLIFIER (EA1- Input, Pin 2; EA1+

Input, Pin 4; EA1 Output, Pin 8) -- The Error

Amplifier is an uncommitted LM158-type operational

amplifier, providing the user with many external

control loop compensation options. This amplifier is

compensated for unity gain stability, so it can be

used as a unity gain input buffer to the internal

PWM comparator when pin 2 is connected to pin 8.

The output of the Error Amplifier is internally connected

to the PWM comparator's "-" input, simplifing external

layout connections.

+5V REFERENCE OUTPUT (Pin 5) -- This output

provides a temperature-compensated, regulated

voltage reference for critical external loads. It is

recommended that this pin be used to power the

external Hall-effect motor position sensors. By design,

the +5V reference must be in regulation before the

remainder of the control circuitry is activated. This

feature allows the Hall-effect sensors to become

powered and enabled before any Phase Output is

enabled in the OM9373 preventing damage at turn-

on. High-frequency bypass capacitors (10uF polarized

in parallel with 0.1uF ceramic are recommended)

should be connected as close as possible to pin 5

and Ground (pin 19).

SPARE AMPLIFIER (EA2- Input, Pin 6; EA2+

Input, Pin 3; EA2 Output, Pin 7) -- The Spare

Amplifier is an uncommitted LM158-type operational

amplifier, and in addition to the internal error

amplifier, provides the user with additional external

control loop compensation options. This amplifier is

also compensated for unity gain stability and it can

be used as a unity gain input buffer when pin 6 is

connected to pin 7. If the Spare Amplifier is unused,

pin 3 should be connected to Ground, and pin 6

should be connected to pin 7.

OSCILLA T OR TIMING INPUT (Pin 10) -- The Oscillator

Timing Input sets a fixed PWM chopping frequency

by means of an internal resistor (Rosc), whose

value is set to 75kΩ, connected from pin 10 to the +5V

Reference Output, and an internal capacitor (Cosc),

whose value is 1800pF, connected from pin 10 to

Ground. In custom applications, the recommended

range of values for Rosc is 10kΩ to 100kΩ, and for

Cosc is 0.001uF to 0.01uF and the maximum operating

frequency should be kept below 20kHz. The appro ximate

oscillator frequency is:

The voltage waveform on pin 10 is a ramp whose

magnitude is approximately 1.2Vp-p, centered at

approximately 1.6Vdc. In addition to the voltage-

mode PWM control, pin 10 may be used for slope

compensation in current-mode control applications.

ISENSE (Pin 11) -- This pin is connected to the

output of the internal current-sense amplifier. It

drives a peak-current (cycle-by-cycle) comparator

which controls Phase Output chopping, and a fail-

safe current comparator which, in the event of an

output overcurrent condition, activates the soft-start

feature and disables the Phase Outputs until the

overcurrent condition is removed. The magnitude of

the voltage appearing at pin 11 is dependent upon

the voltages present at the current-sense amplifier

inputs, ISH and ISL:

V(Isense) = 2.5V + [2 x ABS (ISH - ISL)] [ V ]

CURRENT SENSE INPUTS (ISH, Pin 12; ISL, pin 13)

PWM INPUT (Pin 9) -- This pin is connected to the

"+" input of the internal PWM comparator. The PWM

output clears the internal PWM latch, which in turn

commands the Phase Outputs to chop. For voltage-

mode control systems, pin 9 may be connected to

the Oscillator Timing Input, pin 10.

These inputs to the current-sense amplifier are inter

changeable and they can be used as differential

inputs. The differential voltage applied between pins

12 and 13 should be kept below +/-0.5Vdc to avoid

saturaion.

fo = ( Rosc x Cosc )

2[ Hz ]

OM9373

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TACHOMETER OUTPUT (Pin 15) -- This output

provides a fixed width 5V pulse when any Hall-

eff ect Input (1, 2 or 3) changes state. The pulse width

of the Tachometer Output is set internally in the

OM9373 to 113µs (nominal). The average value of

the output voltage on pin 15 is directly proportional

to the motor's speed, so this output may be used

(with an external averaging filter) as a true tachometer

output, and fed back to the Speed Input (pin 23) to

sense the actual motor speed.

Note: Whenever pin 15 is high, the internal Hall-effect

position latches are inhibited (i.e. "latched"), to reject

noise during the chopping portion of the commutation

cycle, and this makes additional com mutations

impossible. This means that in order to prevent false

commutation at a speed less than the desired maximum

speed, the highest speed as observ ed at the Tachometer

Output should be set above the expected maximum

value.

BRAKE / TACH TIMING INPUT (Pin 16) -- The

Brake/Tach Timing Input is a dual-purpose input.

Internal to the OM9373 are timing components tied

from pin 16 to Ground (a 51kΩ resistor and a 3300pF

capacitor) These components set the minimum pulse

width of the Tachometer Output to 113µs, and this

time may be adjusted using external components,

according to the equation:

T(tach) = 0.67 x (Ct + 3300pf) x (Rt x 51k Ω Ω

Ω Ω

Ω )(µs)

The recommended range of external resistance (to

Ground) is 15kΩ to ∞, and the range of external

capacitance (to Ground) is 0pF to 0.01uF. With each

Tachometer Output pulse, the capacitor tied to pin

16 is discharged from approximately 3.33V to

QUAD SELECT INPUT (Pin 14) -- This input is used

to set the OM9373 in a half control or full control

chopping regime. When driven with a logic low level,

the OM9373 is in the half control mode, whereby only

the three lower (pull-down) power switches associated

with the Phase Outputs are allow ed to chop. Alternately,

when driven with a logic high level, the OM9373 is

in the full control mode, where all six power switches

(pull-up and pull-down) associated with the Phase

Outputs are chopped by the PWM. During motor braking,

changing the logic state of the Quad Select Input

has no effect on the operation of the OM9373.

Rt + 51kΩΩ

ΩΩ

Ω

approximately 1.67V by an internal timing resistor.

The Brake / Tach Timing Input has another function.

If this pin is pulled below the brake threshold

voltage, the OM9373 will enter the brake mode. The

brake mode is defined as the disabling of all three

high-side (pull-up) drivers associated with the Phase

Outputs, and the enabling of all three low-side (pull-

down) drivers.

OVERVOLTAGE / COAST INPUT (Pin 17) -- This

input may be used as a shutdown or an enable/

disable input to the OM9373. Also, since the switching

inhibit threshold is so tightly defined, this input can

be directly interfaced with a resistive divider which

senses the voltage of the motor supply, Vm, for

overvoltage conditions. A high level (greater than th e

inhibit threshold) on pin 17 causes the coast condition

to occur, whereby all Phase Outputs revert to a Hi-Z

state and any motor current which flowed prior to the

Overvoltage/ Coast command and is commutated via the

power "catch" rectifiers associated with each Phase

Output.

SOFT-START INPUT (Pin 18) -- The Soft-Start input

is internally connected to a 10µA (nominal) current

source, the collector of an NPN clamp/discharge

transistor, and a voltage comparator whose soft-

start/restart threshold is 0.2Vdc (nominal). An

external capacitor is connected from this pin to

Ground (pin 19). Whenever the Vcc supply input

drops below the turn-on threshold, approximately

9Vdc, or the sensed current exceeds the over-

current threshold, approximately 0.3V at the current

sense amplifier , the soft-start latch is set. This driv es

the NPN clamp transistor which discharges the

external soft-start capacitor. When the capacitor

voltage drops below the soft-start/restart threshold

and a fault condition does not exist, the soft-start

latch is cleared; the soft-start capacitor charges via

the internal current source.

In addition to discharging the soft-start capacitor , the

clamp transistor also clamps the output of the error

amplifier internal to the controller IC, not allowing

the voltage at the output of the error amplifier to

exceed the voltage at pin 18, regardless of the

inputs to the amplifier. This action provides for an

orderly motor start-up either at start-up or when

recovering from a fault condition.

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OM9373

GROUND (Pin 19) - The voltages that control the

OM9373 are referenced with respect to this pin. All

bypass capacitors, timing resistors and capacitors,

loop compensation components, and the Hall-effect

filter capacitors must be referenced as close as

possible to pin 19 for proper circuit operation.

Additionally, pin 19 must be connected as close as

physically possible to the Motor Return, pins 27 and

28.

HALL-EFFECT INPUTS (H1, Pin 22; H2, Pin 21; H3,

Pin 20) - Each input has an internal pull-up resistor

to the +5V Reference. Each input also has an

internal 180pF noise filter capacitor to Ground. In

order to minimize the noise which may be coupled

from the motor commutation action to these inputs, it

is strongly recommended that additional external

filter capacitors, whose value is in the range of

2200pF, be connected from each Hall-Effect Input

pin to Ground. Whatever capacitor value is used, the

rise/fall times of each input must be guaranteed to

be less than 20us for proper tachometer action to

occur. Motors with 60 degree position sensing may

be used if one or two of the Hall-effect sensor

signals is inverted prior to connection to the Hall-

Effect Inputs.

SPEED INPUT (Pin 23) - This pin is connected to the

“+” input of a voltage comparator, whose threshold

is 0.25Vdc. As long as the Speed Input is less than

0.25V, the direction latch is transparent. When the

Speed Input is greater than 0.25V, then the direction

latch inhibits all changes in direction. It is recommeded,

especially while operating in the half control mode,

that the Tachometer Output is connected to the

Speed Input via a low-pass filter, such that the

direction latch is transparent only when the motor is

spinning very slowly. In this case, the motor has too

little stored energy to damage the power devices

during direction reversal.

DIRECTION INPUT (Pin 24) - This input is used to

select the motor direction. This input has an internal

protection feature: the logic-level present on the

Direction Input is first loaded into a direction latch,

then shifted through a two-bit shift register before

interfacing with the internal output phase driver

logic decoder. Also, protection circuitry detects

when the input and the output of the direction latch

or the 2-bit shift register are different, and inhibits

the Phase Outputs (i.e . Hi-Z) during those times. This

feature may be used to allow the motor to coast to a

safe speed before a direction reversal takes place.

Power stage cross-conduction ( current "shoot-through”

from Vmotor to Ground through simultaneously enabled

pull-up and pull-down drivers ) is prevented by the shift

fixed delay of between one and two PWM oscillator clock

cycles occurs. This delay or "dead-time" guarantees that

power-stage cross-conduction will not occur.

CURRENT SENSE OUTPUTS (CSH, Pin 25; CSL,

Pin 26) - The Current Sense Outputs produce a

differential voltage equal to the motor current times

the sense resistance value (5mΩ nominal). There is

an internal 0.018µF filter capacitor across pins 25

and 26, and two 100Ω series resistors, one between

each pin and each end of the current sense resistor.

To configure the current sense amplifier for cycle-

by-cycle current limiting and/or overcurrent p r otection,

connect pin 25 to pin 12 (ISH) and pin 26 to pin 13

(ISL).

MOTOR RETURN (Pins 27 and 28) - These pins are

connected to the most negative terminal of the

motor supply (Vm-). This connection is electrically

isolated from the logic ground internal to the OM9373

package to minimize, if not eliminate, noise on the

logic ground. The connection to the logic ground is

made by the user external to the package (refer to

Ground (pin 19)). In order to minimize packaing

losses and parasitic effects, it is essential that both

of these pins be firmly connected to the motor supply

Ground, with as short a connection as physically

possible.

SOURCE (Pins 29, 34, 35, 39 and 40) - The source

pins form the low-side connection of the pull-down

switches associated with each Phase Output. Because

of the switching current capability of the OM9373, all

5 pins should be externally connected together with

a low impedance bus to minimize losses and voltage

differentials. Also, due to layout design considerations,

pin 29 is internally connected to the "top" of the internal

current-sense resistor.

OM9373

12 www.irf.com

PHASE OUTPUTS (Phase A, Pins 41 and 42;

Phase B, Pins 36 and 37; Phase C, Pins 31 and 32)

These outputs are connected to either Vmotor via

the pull-up driver or Source via the pull-down driver,

depending upon the Hall-Effect and Direction Inputs

(see Commutation Truth Table). The two pins associated

with each Phase Output must be connected to one of the

three phases of the motor driven by the OM9373.

VMOTOR (Pins 33, 38, and 43) - These pins are

connected to the most positive terminal of the motor

supply (Vm+). For proper operation, all three pins

must be connected together externally with a low

impedance power bus. The Vmotor power bus

should be bypassed with an adequately voltage-

rated ceramic capacitor, 0.1µF (typical), and a low-

ESR electrolytic capacitor, whose capacitance can

be selected by the following: 10µF-per-Ampere of

average motor current from Vmotor to Motor Retur n.

Note: All connections, including the power bus

capacitor connections, must be made as close as

possible to the Vmotor and Motor Return pins to

minimize parasitic effects.

Pin Designation

Pin No. Designation Pin No. Designation Pin No. Designat ion Pin No. Designat ion

1VCC 12 ISH 23 Speed Input 34 Source B

2 E A 1 "- " In put 13 I S L 24 D irect i on In put 3 5 S ource B

3 EA2 "+" In put 14 Qua d Sele ct Input 25 CSH 36 Phase B Output

4 EA1 "+" In put 15 Tachomet er O ut put 26 CSL 37 Phase B Ou tp ut

5+5V Reference Output 16 Brake/Tach Timing Input 27 Motor Return 38 Vmotor

6 EA2 "-" Input 17 Overvoltage/Coast Input 28 Motor R et ur n 39 Source A

7 E A2 Output 18 Soft- Sta r t I nput 29 S ourc e C 40 S ource A

8 EA1 Output 19 Ground 30 ( No Connection) 41 Phase A Output

9 PWM Input 20 H3 Input 31 Phase C Output 42 Phase A Output

10 Oscillator Timing Input 21 H2 In put 32 Phase C O ut put 43 Vmotor

11 Isense 22 H 1 In put 33 Vmotor Case (No Con nection)

www.irf.com 13

OM9373

Commutation Truth Table

Table 1 - Commutation Truth Ta bl e

Dir H1 H2 H3 A B C

1 0 0 1 Hi-Z Sink Source

1 0 1 1 Sink Hi-Z Source

1 0 1 0 Sink Source Hi-Z

1 1 1 0 Hi-Z Source Sink

1 1 0 0 Source Hi-Z Sink

1 1 0 1 Source Sink Hi-Z

0 1 0 1 Sink Source Hi-Z

0 1 0 0 Sink Hi-Z Source

0 1 1 0 Hi-Z Sink Source

0 0 1 0 Source Sink Hi-Z

0 0 1 1 Source Hi-Z Sink

0 0 0 1 Hi-Z Source Sink

X 0 0 0 Hi-Z Hi-Z Hi-Z

X 1 1 1 Hi-Z Hi-Z Hi-Z

Digital Inpu t s Phase Outpu t s

Tab le 1 shows the Phase Output state versus the state

of the Hall-Effect and Direction Inputs. Please note

that the OM9373 Hall-Effect Inputs are Grey-encoded;

that is, only one input is allowed to change from one

input state to another at a time.

The commutation coding shown reflects Hall-Effect

sensors that are spaced at 120° mechanical

increments. Also, internal protection logic disables

all three Phase Outputs when the Hall-Effect Inputs

are set to an illegal condition (i.e. all logic low or all

logic high).

The OM9373 is offered in F-43, a hermetic flatpack

package as well as in MP3-43L, a plastic ring frame,

low profile flatpack package.

The hermetic version is offered in two standard

screening levels: a full military temperature range of

-55°C to +125°C with limited screening and with

Package and Screening Options MIL-STD-883 screening. The plastic ring frame ver-

sion is offered in an industrial temperature range of

-40°C to +85°C with limited screening.

The screening levels for the SFB, SFP and SPP

versions are listed in the table below. All tests and

inspections are in accordance with those listed in

MIL-STD-883.

Test / Inspection SFB SFP SPP

Precap Vi sual Inspection 100% 100% 100%

T em pera t ure Cycl e 100% NA NA

Mech anical Shock 100% NA NA

He r m etici t y ( F ine an d G r os s Leak ) 100% 1 00 % NA

P r e Burn- In Electr ica l 100% NA NA

B ur n-In ( 160 hours ) 100% NA NA

Final Electrical Test -55 °C, 25° C , +1 25°C +25°C +25° C

Group A Testing 100% NA N A

Final Visual In specti on 100% 100% 100%

OM9373

14 www.irf.com

IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105

IR LEOMINSTER: 205 Crawford St., Leominster, Massachusetts 01453, USA Tel: (978) 534-5776

Visit us at www.irf.com for sales contact information.

Data and specifications subject to change without notice. 11/03

Mechanical Outline - F-43 ( OM9373SF )

Mechanical Outline - MP3-43L ( OM9373SP )

aPin 1 Pin 43

Pin 26

a Pin 1 Pin 43

Pin 26