A3969 View Datasheet(PDF) - Allegro MicroSystems

Part Name

Description

Manufacturer

A3969

Dual Full-Bridge PWM Motor Driver

Allegro MicroSystems 

A3969

Dual Full-Bridge PWM Motor Driver

Features and Benefits

▪ ±650 mA Continuous Output Current

▪ 30 V Output Voltage Rating

▪ Internal Fixed-Frequency PWM Current Control

▪ Satlington Sink Drivers

▪ User-Selectable Blanking Window

▪ Internal Ground-Clamp and Flyback Diodes

▪ Internal Thermal-Shutdown Circuitry

▪ Crossover-Current Protection and UVLO Protection

Continued on the next page…

Package: 28 pin QFN (suffix ET)

Approximate scale

Description

The A3969 is designed to drive both windings of a two-phase

bipolar stepper motor. The device includes two H-bridges

capable of continuous output currents of ±650 mAand operating

voltages to 30 V. Motor winding current can be controlled by

the internal fixed-frequency, pulse-width modulated (PWM),

current-control circuitry. The peak load current limit is set by

the user’s selection of a reference voltage and current-sensing

resistors.

The fixed-frequency pulse duration is set by a user-selected

external RC timing network. 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.

To reduce on-chip power dissipation, the H-bridge power

outputs have been optimized for low saturation voltages. The

sink drivers feature the Allegro® patented Satlington® output

structure. The Satlington outputs combine the low voltage drop

of a saturated transistor and the high peak current capability

of a Darlington.

Continued on the next page…

Typical Application

56 kΩ

+3.3 V

+24 V

680 pF

+3.3 V

20 kΩ

10 kΩ

47 μF

EN2

PH2

0.5 Ω

1

21

2

20

0.5 Ω

3

19

4

LOGIC

LOGIC

18

5

17

6

16

7

VBB

15

EN1

PH1

DS3969

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