Description

The A3988 is a quad DMOS full-bridge driver capable of

driving up to two stepper motors or four dc motors. Each

full-bridge output is rated up to 1.2 A and 36 V. The A3988

includes fixed off-time pulse width modulation (PWM) current

regulators, along with 2- bit nonlinear DACs (digital-to-analog

converters) that allow stepper motors to be controlled in full,

half, and quarter steps, and dc motors in forward, reverse, and

patented mixed decay mode for reduced audible motor noise,

increased step accuracy, and reduced power dissipation.

Internal synchronous rectification control circuitry is provided

to improve power dissipation during PWM operation.

Protection features include thermal shutdown with hysteresis,

undervoltagelockout(UVLO)andcrossovercurrentprotection.

Special power up sequencing is not required.

The A3988 is supplied in two packages, EV and JP, with

exposed power tabs for enhanced thermal performance. The

EV is a 6 mm x 6 mm, 36 pin QFN package with a nominal

overall package height of 0.90 mm. The JP is a 7 mm × 7 mm

48 pin LQFP. Both packages are lead (Pb) free, with 100%

matte tin leadframe plating.

A3988DS, Rev. 5

Features and Benefits

▪ 36 V output rating

▪ 4 full bridges

▪ Dual stepper motor driver

▪ High current outputs

▪ 3.3 and 5 V compatible logic supply

▪ Synchronous rectification

▪ Internal undervoltage lockout (UVLO)

▪ Thermal shutdown circuitry

▪ Crossover-current protection

▪ Low profile QFN package

Quad DMOS Full Bridge PWM Motor Driver

Packages

A3988

Approximate scale

Figure 1. Typical application circuit

PHASE1

I01

I11

SENSE1

OUT2A

OUT1A

SENSE2

OUT2B

OUT1B

VDD

SENSE4

OUT4B

OUT4A

SENSE3

OUT3B

OUT3A

VREF2

PHASE2

VREF1

VREF4

VREF3

I02

I12

PHASE3

I03

I13

PHASE4

I04

I14

0.1 μF

50 V

100 μF

50 V

0.22 μF

50 V

0.1 μF

50 V

A3988

Bipolar Stepper Motors

Microprocessor

Package EV, 36 pin QFN

0.90 mm nominal height

with exposed thermal pad

Package JP, 48 pin LQFP

with exposed thermal pad