Allegro Announces DMOS Full-Bridge Motor Driver With Over-Current Protection
Allegro MicroSystems Inc. announces a new Double-Diffused Metal-Oxide Semiconductor full-bridge motor driver to complement its parallel input dc motor driver family. Designed for pulse width modulated (PWM) control of dc motors, the A3950 is capable of peak output currents to ±2.8 A and operating voltages to 36 V. The A3950 is targeted at the office automation, industrial and medical markets.
Phase and enable input terminals are provided for use in controlling the speed, and the direction of rotation and torque of a dc motor with externally applied PWM control signals. Internal synchronous rectification control circuitry reduces power dissipation by switching on appropriate DMOS outputs to effectively short out the body diodes during PWM operation. This internal control technique can reduce output power dissipation by 10% to 30% in most applications.
The A3950 has an over-current protection (OCP) feature that prevents IC damage during motor lead short to supply and ground conditions. Other internal circuit protection features include thermal shutdown with hysteresis, undervoltage lockout of the motor supply and charge pump output, and crossover current protection. A diagnostic, open drain output is provided to indicate fault conditions.
The A3950 is supplied in a small (5 x 4.4 x 1.2 mm), lead-free, 16L eTSSOP (suffix "LP-T") package with exposed power tab. The eTSSOP package is less than one-fourth the size of competing devices in the market, company officials said.
Allegro's A3950 is priced at $1.40 in quantities of 10,000 and has a 14-week lead-time to market.
Allegro MicroSystems Inc. is a supplier of advanced mixed-signal power semiconductors and Hall-effect sensors targeted toward the automotive, communications, computer/office automation, consumer and industrial markets.
