A3950 DMOS Full-Bridge Motor Driver With Over-Current Protection

A DMOS full-bridge motor driver to complement their 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 (PB) free, 16L eTSSOP (suffix “LP-T”) package with exposed power tab. The eTSSOP package is less than 1/4 the size of competing devices in the market. Please note that the small size does not limit its thermal performance.