FULL-BRIDGE PWM MOTOR DRIVER

Designed for bidirectional pulse-width modulated current control of

inductive loads, the A3952S– is capable of continuous output currents

to

±2 A and operating voltages to 50 V. Internal fixed off-time PWM

current-control circuitry can be used to regulate the maximum load

current to a desired value. The peak load current limit is set by the

user’s selection of an input reference voltage and external sensing

resistor. The fixed OFF-time pulse duration is set by a user-selected

external RC timing network. Internal circuit protection includes thermal

shutdown with hysteresis, transient suppression diodes, and crossover-

current protection. Special power-up sequencing is not required.

With the ENABLE input held low, the PHASE input controls load

current polarity by selecting the appropriate source and sink driver pair.

The MODE input determines whether the PWM current-control circuitry

operates in a slow current-decay mode (only the selected sink driver

switching) or in a fast current-decay mode (selected source and sink

switching). A user-selectable blanking window prevents false triggering

of the PWM current control circuitry. With the ENABLE input held high,

all output drivers are disabled. A sleep mode is provided to reduce

power consumption when inactive.

When a logic low is applied to the BRAKE input, the braking

function is enabled. This overrides ENABLE and PHASE to turn OFF

both source drivers and turn ON both sink drivers. The brake function

can be safely used to dynamically brake brush dc motors.

The A3952S– is supplied in a choice of four power packages. In all

package styles, the batwing/power tab is at ground potential and needs

no isolation. These devices are also available for operation from -40

°C

to +125

°C. To order, change the suffix from 'S–' to 'K–'.

FEATURES

s

±2 A Continuous Output Current Rating

s

50 V Output Voltage Rating

s

Internal PWM Current Control

s

Fast and Slow Current-Decay Modes

s

Sleep (Low Current Consumption) Mode

s

Internal Transient Suppression Diodes

s

Under-Voltage Lockout

s

Internal Thermal Shutdown Circuitry

s

Crossover-Current Protection

Always order by complete part number:

Part Number

Package

A3952SB

16-Pin DIP

43

°C/W

6.0

°C/W

A3952SEB

28-Lead PLCC

42

°C/W

6.0

°C/W

A3952SLB

16-Lead SOIC

67

°C/W

6.0

°C/W

A3952SW

12-Pin Power-Tab SIP

36

°C/W

2.0

°C/W

A3952SB

Note that the A3952SB (DIP) and the A3952SLB

(SOIC) are electrically identical and share a

common terminal number assignment.

ABSOLUTE MAXIMUM RATINGS

Load Supply Voltage, V

Output Current, I

OUT

(t

(Continuous) ...............................

Logic Supply Voltage, V

Logic Input Voltage Range,

V

Sense Voltage, V

Reference Voltage, V

Package Power Dissipation,

P

Operating Temperature Range,

T

Junction Temperature, T

Storage Temperature Range,

T

Output current rating may be limited by duty cycle,

ambient temperature, heat sinking and/or forced

cooling. Under any set of conditions, do not

exceed the specified current rating or a junction

temperature of +150

°C.

* Fault conditions that produce excessive junction

temperature will activate device thermal shutdown

circuitry. These conditions can be tolerated but

should be avoided.

3952

MODE

GROUND

GROUND

LOGIC

SUPPLY

PHASE

GROUND

GROUND

RC

SENSE

LOAD

SUPPLY

Dwg. PP-056

BRAKE

REF

LOAD

SUPPLY

OUTB

OUTA

LOGIC

ENABLE

1

2

3

4

5

6

7

89

10

11

12

13

14

15

16