A3955SB Datasheet PDF - Allegro MicroSystems

●Description

●The A3955 is designed to drive one winding of a bipolar stepper motor in a microstepping mode. The outputs are rated for continuous output currents to ±1.5 A and operating voltages to 50 V. Internal pulse width modulated (PWM) current control combined with an internal three-bit nonlinear digital to-analog converter allows the motor current to be controlled in full-, half-, quarter-, or eighth-step (microstepping) modes. Nonlinear increments minimize the number of control lines necessary for microstepping. Microstepping provides increased step resolution, and reduces torque variations and resonance problems at low speed.

●Features and Benefits

●▪ ±1.5 A continuous output current

●▪ 50 V output voltage rating

●▪ Internal PWM current control

●▪ 3-bit nonlinear DAC

●▪ Fast, mixed fast/slow, and slow current-decay modes

●▪ Internal transient-suppression diodes

●▪ Internal thermal shutdown circuitry

●▪ Crossover-current and UVLO protection