Allegro A3962SLB Datasheet

3962

DUAL FULL-BRIDGE
PWM MOTOR DRIVER

3962

Data Sheet

29319.27

DUAL FULL-BRIDGE PWM MOTOR DRIVER

Designed for pulse-width modulated (PWM) current control of

bipolar stepper motors, the A3962SLB is capable of continuous output

1

OUT

1B

1

OUT

LOAD

REF(IN)

RC

2

1

3

1A

4

5

6

7

9

8

1

9

1

10

1

V

BB

θ

1

PWM 1

SENSE

SUPPLY

GROUND

GROUND

V

PHASE

ENABLE

ABSOLUTE MAXIMUM RATINGS

Load Supply Voltage, VBB. . . . . . . . . 30 V

Output Current, I
Logic Supply Voltage, V
Logic Input Voltage Range,

V

. . . . . . . . . . . -0.3 V to VCC + 0.3 V

IN

Sense Voltage, V
Reference Output Current,

I

. . . . . . . . . . . . . . . . . . . 1.0 mA

REF OUT

Package Power Dissipation,

P

. . . . . . . . . . . . . . . . . . . . See Graph

D

Operating Temperature Range,

T

. . . . . . . . . . . . . . . . -20˚C to +85˚C

A

Junction Temperature, T
Storage Temperature Range,

DISCONTINUED PRODUCT

T

. . . . . . . . . . . . . . . -55˚C to +150˚C

S

* 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 tempera
ture of 150˚C.

† Fault conditions that produce excessive junction

temperature will activate the device’s thermal
shutdown circuitry. These conditions can be
tolerated but should be avoided.

. . . . . . . . . . ±800 mA*

OUT

CC

. . . . . . . . . . . . 1.0 V

SENSE

J

FOR REFERENCE ONLY

20

OUT

2B

2

19

SENSE

2

18

OUT

2A

LOGIC

17

V

CC

SUPPLY

16

GROUND

15

GROUND

14

V

REF(OUT)

13

RC

12

11

2

PHASE

ENABLE

Dwg. PP-047-1

2

PWM 2

θ

2

. . . . . . . . . 7.0 V

. . . . . . . +150˚C†

currents to ±800 mA and operating voltages to 30 V. Internal fixed
off-time PWM current-control circuitry can be used to regulate the
maximum load current to a desired value. An internal precision voltage
reference is provided to improve motor peak-current control accuracy.
The peak load current limit is set by the user’s selection of an external
resistor divider and current-sensing resistors.

The fixed off-time pulse duration is set by user-selected external
RC timing networks. The capacitor in the RC timing network also
determines a user-selectable blanking window that prevents false
triggering of the PWM current control circuitry during switching transi­tions. This eliminates the need for two external RC filter networks on
the current-sensing comparator inputs.

2

For each bridge the PHASE input controls load current polarity by
selecting the appropriate source and sink driver pair. For each bridge
the ENABLE input, when held high, disables the output drivers. Spe­cial power-up sequencing is not required. Internal circuit protection
includes thermal shutdown with hysteresis, transient-suppression
diodes, and crossover-current protection.

The A3962SLB is supplied in a 20-lead plastic SOIC with copper
heat sink tabs. The power tab is at ground potential and needs no
electrical isolation.

FEATURES

■ ±800 mA Continuous Output Current Rating

■ 30 V Output Voltage Rating

■ Internal PWM Current Control, Saturated Sink Drivers

■ Internally Generated Precision 2.5 V Reference

■ Internal Transient-Suppression Diodes

■ Internal Thermal-Shutdown Circuitry

■ Crossover-Current Protection, UVLO Protection

■ Automotive Capable

— See A3964SLB

Always order by complete part number: A3962SLB .

3962

DUAL FULL-BRIDGE
PWM MOTOR DRIVER

2.5

R = 6°C/W

2.0

1.5

R = 60°C/W

1.0

0.5

0

25

ALLOWABLE PACKAGE POWER DISSIPATION in WATTS

θJA

50 75 100 125 150

TEMPERATURE in °C

θJT

FUNCTIONAL BLOCK DIAGRAM AND TYPICAL

BIPOLAR STEPPER MOTOR APPLICATION

MOTOR SUPPLY

C

BB

Dwg. GP-019-1

V

BB

ENABLE PHASE OUT

H X Off Off
LHHL
LLLH

X = Irrelevant

V

CC

C

TRUTH TABLE

LOGIC SUPPLY

CC

OUT

A

B

1A

OUT

OUT

1B

ENABLE 1

PHASE 1

CONTROL LOGIC
AND LEVEL SHIFT

BLANKING

TIME AND

SOURCE

DRIVER T

CONTROL

RC

1

R

T1

OFF

SENSE

C

T1

OUT

2A

OUT

2B

ENABLE 2

CONTROL LOGIC
AND LEVEL SHIFT

UVLO

AND

+

_

TSD

VOLTAGE

REFERENCE

BLANKING

+

_

TIME AND

SOURCE

DRIVER T

OFF

PHASE 2

CONTROL

1

GND

R

S1

REF

OUT

R

1

REF

R

IN

2

SENSE

RC

S2

2

T2

RC

2

R

T2

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
Copyright © 1995 Allegro MicroSystems, Inc.

3962

DUAL FULL-BRIDGE
PWM MOTOR DRIVER

ELECTRICAL CHARACTERISTICS at T

= +25°C, V

A

= 30 V, VCC = 4.75 V to 5.25 V, V

BB

SENSE

V, 30 kΩ & 1000 pF RC to Ground (unless noted otherwise)

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Output Drivers

Load Supply Voltage Range V
Output Sustaining Voltage V
Output Leakage Current I

Output Saturation Voltage V

Clamp Diode Forward Voltage V

BB

CE(sus)

CEX

CE(SAT)

F

(Sink or Source) IF = 750 mA — 1.3 1.6 V

Operating, I
I

= ±800 mA, L = 3 mH — — 30 +V

OUT

V

= V

OUT

V

= 0 V — <1.0 -50 µA

OUT

Source Driver, I
Source Driver, I
Source Driver, I
Sink Driver, I
Sink Driver, I
Sink Driver, I

= ±800 mA, L = 3 mH 5.0 — 30 V

OUT

BB

= -500 mA — 1.0 1.2 V

OUT

= -750 mA — 1.1 1.5 V

OUT

= -800 mA — — 1.7 V

OUT

= +500 mA — 0.3 0.6 V

OUT

= +750 mA — 0.5 1.2 V

OUT

= +800 mA — — 1.5 V

OUT

— <1.0 50 µA

F

IF = 500 mA — 1.1 1.4 V

= 0

V

Motor Supply Current I
(No Load) I

Control Logic

Logic Supply Voltage Range V
Logic Input Voltage V

Logic Input Current I

BB(ON)

BB(OFF)

CC

IN(1)

V

IN(0)

IN(1)

I

IN(0)

IF = 800 mA — — 1.7 V
V
V

= 0.8 V — 5.0 7.0 mA

ENABLE

= 2.4 V — 5.0 7.0 mA

ENABLE

Operating 4.75 — 5.25 V

2.4 — — V
— — 0.8 V

V

= 2.4 V — <1.0 20 µA

IN

V

= 0.8 V — <-2.0 -200 µA

IN

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