The A3979 microstepping motor driver operates bipolar stepper motors in full, half, quarter, and sixteenth-step modes, with output drive capability of 35 V and ±2.5 A. It is a drop-in replacement for the A3977SLP with 16 microsteps/step resolution. An internal translator converts one-pulse step inputs to one microstep without phase sequence tables, high-frequency control lines, or complex interfaces. The driver uses a two-input step and direction interface. Internal synchronous rectifier circuitry reduces power dissipation during PWM operation and eliminates the need for external Schottky diodes. The driver is available in both leaded and lead-free versions.

Allegro MicroSystems Inc., 115 Northeast Cutoff, Worcester, MA 01606, (508) 853-5000,