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3976

The A3976 is designed to drive both windings of a bipolar stepper

motor or bidirectionally control two DC Motors. Both H-Bridges are capable

of continuous output currents of up to +/- 500 mA and operating voltages to

30V. Free wheeling, substrate isolated diodes are included for output transient

suppression when switching motors or other inductive loads. For each bridge

the PHASE input controls load current polarity by selecting the appropriate

source and sink driver pair. The ENABLE input, when held high, enables the

respective output H-bridge. When both ENABLE pins are held low the device

will enter SLEEP mode and consume less than 100

µA.

The 3976 is protected to ensure safe operation in harsh operating

environments and was designed specifically for automotive applications.

Protection circuitry will check for open or shorted load, motor lead short to

ground or supply, VBB overvoltage, VCC undervoltage, and thermal

shutdown. If any of these conditions are detected the outputs will be disabled

and fault information will be output to diagnostic pins FAULT1 and FAULT2.

The 3976 is supplied in a choice of two power packages, a 16-lead

plastic DIP with a copper batwing tab (suffix ‘B’), and a 24-lead plastic SOIC

with a copper batwing tab (suffix ‘LB’). In both cases, the power tab is at

ground potential and needs no electrical isolation.

FEATURES

n 30 V , ±500 mA Continuous Output Rating

n 35V Load Dump Survival

n Output Short Circuit Protection

n Coded Fault Diagnostic Outputs

n Low Current Standby Mode

n Open Load Monitor

n Low Current Standby Mode

n VBB Over Voltage Shutdown

n Internal Thermal Shutdown Circuitry

n Internal Low Parasitic Free Wheeling Diodes

n Crossover Current Protection

4

3

2

1

8

6

7

5

12

11

10

9

21

22

23

24

17

19

18

20

13

14

15

16

ENABLE1

V

BB

PHASE1

n/c

n/c

GROUND

GROUND

n/c

OUT1A

n/c

FAULT1

OUT1B

PHASE2

n/c

V

CC

ENABLE2

FAULT2

OUT2B

OUT2A

n/c

n/c

GROUND

n/c

GROUND

A3976KLB

ABSOLUTE MAXIMUM RATINGS

at TA = +25°C

Non-Operating Supply Voltage..................... 35 V

±500 mA*

Fault Output Voltage ................................... 7.0 V

Logic Input Voltage Range,

A3976KLB.................................. 2.2 W

A3976KB .................................... 2.9 W

Operating Temperature Range,

Storage Temperature Range,

* Output current rating may be limited by duty cycle,

ambient temperature, and heat sinking. Under any set of

conditions, do not exceed the specified current rating or a

junction temperature of 150

°C.

PART NUMBER

PACKAGE

A3976KLB

24 Lead SOIC

56

°°C/W

6

°°C/W

A3973KB

16 Lead DIP

43

°°C/W

6

°°C/W

ADVANCED DATASHEET - 02/19/99

(Subject to change without notice)

DUAL FULL BRIDGE

PROTECTED MOTOR DRIVER