Full-Bridge PWM Motor Driver

A4973

2

Allegro MicroSystems, LLC

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Description (continued)

Absolute Maximum Ratings

Characteristic

Symbol

Notes

Rating

Units

Load Supply Voltage

50

V

Logic Supply Voltage

6V

Logic/Reference Input Voltage Range

–0.3 to 6

V

Sense Voltage

0.5

V

Output Current, Continuous

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.

±1.5

A

Transient Output Current

A

Package Power Dissipation

See graph

W

Operating Ambient Temperature

Range S

–20 to 85

ºC

Maximum Junction Temperature

Fault conditions that produce excessive junction temperature

will activate the device’s thermal shutdown circuitry. These

conditions can be tolerated but should be avoided.

150

ºC

Storage Temperature

–55 to 150

ºC

Selection Guide

Part Number

Package

Packing

A4973SB-T

16-pin DIP with exposed thermal tabs

25 pieces per tube

A4973SLBTR-T

16-pin SOICW with internally-fused pins

1000 pieces per reel

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 used to dynamically brake brush DC motors.

The A4973 is supplied in a choice of two power packages; a

16-pin dual-in-line plastic package with copper heat-sink tabs,

and a 16-pin plastic SOIC with copper heat-sink tabs. For both

package styles, the power tab is at ground potential and needs no

electrical isolation. Each package type is available in a lead (Pb)

free version (100% matte tin plated leadframe).

Thermal Characteristics

Characteristic

Symbol

Test Conditions*

Value

Units

Package Thermal Resistance, Junction

to Ambient

43

ºC/W

side

67

ºC/W

Package Thermal Resistance, Junction

to Tab

6

ºC/W

*Additional thermal information available on Allegro website.

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

50

75

100

125

150

1

0

TEMPERATURE IN °C

4

3

2

25

R

= 6.0°C/W

θJT

SUFFIX 'B', R

= 43°C/W

θJA

SUFFIX 'LB', R

= 67°C/W

θJA

Note the A4973SB (DIP) and

the A4973SLB (SOIC) are

electrically identical and share

a common terminal number

assignment.