Digitally Programmable

Dual Full-Bridge MOSFET Driver

A3985

2

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

control for a variety of step methods, from microstepping to full-step

drive. Load current in the external power MOSFET full-bridges is

set in 1.56% increments of the maximum value.

The above-supply voltage required for the high-side N-channel

MOSFETs is provided by a bootstrap capacitor. Efficiency is

enhanced by using synchronous rectification and the power FETs

are protected from shoot-through by integrated crossover-control

and programmable dead time.

In addition to crossover current control, internal circuit protection

providesthermalshutdownwithhysteresisandundervoltagelockout.

Special power-up sequencing is not required. This component is

supplied in a 38-pin TSSOP (package LD) with 100% matte tin

leadframe plating.

Description (continued)

Selection Guide

Part Number

Packing*

A3985SLD-T

Tube, 50 pieces per tube

A3985SLDTR-T

Tape and reel, 4000 pieces per reel

*Contact Allegro for additional packing options

Absolute Maximum Ratings

Characteristic

Symbol

Notes

Rating

Units

Supply Voltage

–0.3 to 50

V

Logic Supply Voltage

–0.3 to 7

V

Logic Inputs and Outputs

–0.3 to 7

V

SENSEx pins

–1 to 1

V

Sxx pins

–2 to 55

V

LSSx pins

–2 to 5

V

GHxx pins

Sxx to Sxx+15

V

GLxx pins

–2 to 16 V

V

Cxx pins

–0.3 to Sxx+15

V

Operating Ambient Temperature

Range S

–20 to 85

ºC

Junction Temperature

150

ºC

Storage Temperature

–55 to 150

ºC