3948中文资料ALLEGRO数据手册PDF规格书

DMOS FULL-BRIDGE PWM MOTOR DRIVER

Designed for pulse-width modulated (PWM) current control of dc motors, the A3948SB and A3948SLB are capable of continuous output currents to ±1.5 A and operating voltages to 50 V. Internal fixed offtime PWM current-control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed current-decay modes. Similar devices with outputs rated to ±2 A are available as the A3958SB/SLB.

PHASE and ENABLE input terminals are provided for use in controlling the speed and direction of a dc motor with externally applied PWM-control signals. The ENABLE input can be programmed via the serial port to PWM the bridge in fast or slow current decay. Internal synchronous rectification control circuitry is provided to reduce power dissipation during PWM operation.

FEATURES

■ ±1.5 A, 50 V Continuous Output Rating

■ Low rDS(on) Outputs

■ Programmable Mixed, Fast, and Slow Current-Decay Modes

■ Serial Interface Controls Chip Functions

■ Synchronous Rectification for Low Power Dissipation

■ Internal UVLO and Thermal-Shutdown Circuitry

■ Crossover-Current Protection