A4975 Microstepping Drivers

Allegro's A4975 full-bridge PWM microstepping driver is a drop in replacement for the A3955

Image of Allegro MicroSystems' A4975 Microstepping DriversAllegro's A4975 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.

The A4975 is supplied in a choice of two power packages, a 16-pin dual-in-line plastic package with copper heat-sink tabs (suffix B), and a 16-lead plastic SOIC with internally fused pins (suffix LB). For both package styles, the thermally enhanced pins are at ground potential and need no electrical isolation. Both packages are lead (Pb) free, with leadframe plating 100% matte tin.

  • ±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 thermal shutdown circuitry
  • Crossover-current and UVLO protection


ImageManufacturer Part NumberDescriptionPackagingMotor Type - AC, DCAvailable Quantity
A4975SLBTR-T datasheet linkIC MOTOR DRIVER PAR 16SOICA4975SLBTR-TIC MOTOR DRIVER PAR 16SOICCut Tape (CT)-10296 - Immediate
A4975SLBTR-T product page link
A4975SB-T datasheet linkIC MOTOR DRIVER PAR 16DIPA4975SB-TIC MOTOR DRIVER PAR 16DIPTube-2258 - Immediate
A4975SB-T product page link
Published: 2013-07-02