A1448 View Datasheet(PDF) - Allegro MicroSystems

Part Name

Description

Manufacturer

A1448

Low-Voltage, Full-Bridge Brushless DC Motor Driver with Integrated Hall Sensor IC, PWM Speed Control, Soft-Switching, and Reverse Battery and Short Circuit Protection

Allegro MicroSystems 

A1448

Low-Voltage, Full-Bridge Brushless DC Motor Driver with

Integrated Hall Sensor IC, PWM Speed Control, Soft-Switching,

and Reverse Battery and Short Circuit Protection

Functional Description

Soft Switching

The A1448 device includes a soft-switching algorithm that

controls the output switching slew rate for both output pins. As a

result, the A1448 device is ideal for use in applications requiring

low audible switching noise and low EMI. The resistance of the

output transistors is controlled to ensure the smooth switching of

the outputs, as illustrated in figure 1.

CONTROL Pin Functionality: PWM, Braking, and Sleep

Mode Input

The CONTROL input pin accepts an external signal that can

control the speed of the output bridge, initiate active braking,

and put the device into sleep mode. Signals higher than the VINHI

threshold will turn on the output bridge according to the applied

magnetic field. Applying a PWM signal to the CONTROL pin

will turn the bridge on and off according to the PWM duty cycle.

When the CONTROL pin is pulled to GND, the device initiates

its internal active braking algorithm to stop the motor. After

braking, the device enters micro-power sleep mode. The device

becomes active again when the CONTROL pin is pulled higher

than VINHI.

Antistall Algorithm

If a stall condition occurs, the device will execute an antistall

algorithm to re-start the motor.

VOUT2

VOUT1

tSW

Figure 1. A1448 output soft switching with a 30 Ω resistive load

Allegro MicroSystems, Inc.

4

115 Northeast Cutoff

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

1.508.853.5000; www.allegromicro.com

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