Brushless DC motor speed controller
ALLEGRO MICROSYSTEMS

The A1442 is a full-bridge motor driver designed to drive low-voltage, brushless dc motors. Commutation of the motor is achieved by use of a single Hall element sensor to detect the rotational position of an alternating-pole ring magnet. A high-density CMOS semiconductor process allows the integration of all the necessary electronics. This includes the Hall element sensor, the motor control circuitry, and the full output bridge. Low-voltage design techniques have been employed to achieve full device functionality down to low VDD values. This fully integrated single chip solution provides enhanced reliability (including reverse battery protection and output short circuit protection) and eliminates the need for any external support components.

The A1442 employs a soft-switching algorithm to reduce audible switching noise and EMI interference. A micropower sleep mode can be enabled by an external signal, to reduce current consumption for battery management in portable electronic devices. This feature allows the removal of a FET transistor for switching the device on and off.