A3951 Datasheet PDF - Allegro MicroSystems

Designed for bidirectional pulse-width modulated current control of inductive loads, the A3951SB and A3951SW are capable of continuous output currents to ±2 A and operating voltages to 50 V. Internal fixed off-time PWM current-control circuitry can be used to regulate the maximum load current to a desired value. The peak load current limit is set by the user’s selection of an input reference voltage and external sensing resistor. The fixed off-time pulse duration is set by a userselected external RC timing network. Internal circuit protection includes thermal shutdown with hysteresis, transient suppression diodes, and crossover-current protection. Special power-up sequencing is not required. The A3951SB and A3951SW are improved replacements for the UDN2953B and UDN2954W, respectively. For new system designs, the A3952SB/SEB/SLB/SW are recommended.

FEATURES
■ ±2 A Continuous Output Current Rating
■ 50 V Output Voltage Rating
■ Internal PWM Current Control
■ Internal Transient Suppression Diodes
■ Under-Voltage Lockout
■ Internal Thermal Shutdown Circuitry
■ Crossover-Current Protection
■ Default Brake Current Limit