Allegro MicroSystems, Inc. Announces New Low-Voltage Full-Bridge Brushless DC Motor Driver with Integrated Hall With Internal PWM Speed Control

Allegro MicroSystems, Inc. Announces New Low-Voltage Full-Bridge Brushless DC Motor Driver with Integrated Hall With Internal PWM Speed Control

Allegro® has introduced two new full-bridge motor drivers designed to drive low-voltage brushless DC motors in applications that require rotor speed control and fast rotor start-stop cycles. A high density CMOS semiconductor process allows the integration of a Hall element, an H-bridge output driver and PWM speed control logic into a monolithic IC. This fully integrated single-chip solution provides enhanced reliability including reverse battery protection and output short circuit protection.

Commutation of the motor is achieved by use of a single integrated Hall element sensor to detect the rotational position of an alternating-pole ring magnet. Low-voltage design techniques have been employed to achieve full device functionality down to 1.8 V VDD. The voltage applied to the PDC pin is used to externally control the maximum speed of the motor by adjusting the internal PWM duty cycle of the output driver.

Allegro’s A1444/A1445 devices employ a soft-switching algorithm to reduce audible switching noise and EMI interference. The A1444 and A1445 have different, selectable internal PWM Duty Cycle options to accommodate a wide range of motor designs by controlling the state of the PDC input pin, providing external control.