²úÆ·¸ÅÊö£º

Features

• ¡À2 A, 50 V Continuous Output Rating
• Low rDS(on) Outputs (270 milli-ohms, Typical)
• 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

Description

Designed for pulse-width modulated (PWM) current control of dc motors, the A3958SB and A3958SLB are capable of continuous output currents to ¡À2 A and operating voltages to 50 V. Internal fixed off-time PWM current-control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed current-decay modes.

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.

Internal circuit protection includes thermal shutdown with hysteresis, and crossover-current protection. Special power-up sequencing is not required.

Functional Block Diagram