A2918 View Datasheet(PDF) - Allegro MicroSystems

Part Name

Description

Manufacturer

A2918

DUAL FULL-BRIDGE PWM MOTOR DRIVER

Allegro MicroSystems 

General

To avoid excessive voltage spikes on the

LOAD SUPPLY pin (VBB), a large-value

capacitor (≥47 µF) should be connected from

VBB to the ground pin as close as possible to

the device. Under no circumstances should

the voltage at VBB exceed 45 V.

The PHASE input to each bridge

determines the direction motor winding

current flows. An internally generated

deadtime, of approximately 3 µs, prevents

crossover currents that can occur when

switching the PHASE input.

All four drivers in the bridge output can

be turned OFF, with VEN ≥ 2.4, resulting in

a fast current decay through the internal

ground clamp and flyback diodes. The fast

current decay is desirable in half-step and

high-speed applications. The ENABLE input

must be tied low if it is not used.

Varying the reference voltage (VREF)

provides continuous control of the peak load

current.

Thermal protection circuitry turns OFF all

drivers when the junction temperature

reaches approximately +170°C. It is

intended only to protect the device from

failures due to excessive junction

temperature and should not imply that output

short circuits are permitted. The output

drivers are re-enabled when the junction

temperature cools to approximately +145°C.

www.allegromicro.com

2918

DUAL FULL-BRIDGE

PWM MOTOR DRIVER

LOAD CURRENT PATHS

VBB

BRIDGE ON

RS

SOURCE OFF

ALL OFF

Dwg. EP-006-1

The products described here are manufactured in Japan by Sanken

Electric Co., Ltd. for sale by Allegro MicroSystems, Inc.

Sanken Electric Co., Ltd. and Allegro MicroSystems, Inc. reserve the

right to make, from time to time, such departures from the detail

specifications as may be required to permit improvements in the

performance, reliability, or manufacturability of their products.

Therefore, the user is cautioned to verify that the information in this

publication is current before placing any order.

These products are not authorized for use as critical components in

life-support appliances, devices, or systems without express written

approval.

The information included herein is believed to be accurate and

reliable. However, Sanken Electric Co., Ltd. and Allegro

MicroSystems, Inc. assume no responsibility for its use; nor for any

infringements of patents or other rights of third parties which may

result from its use.

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