The Allegro A3957SA and A3957SLB datasheet details specifications, electrical characteristics, and pin functions for a full‑bridge PWM microstepping motor…
The A3957SA and A3957SLB are full‑bridge PWM motor driver ICs designed to drive one winding of a bipolar stepper motor in microstepping mode. They provide continuous output currents up to ±1.5 A, support supply voltages up to 50 V, and include internal PWM current control, a 4‑bit non‑linear DAC, and selectable current‑decay modes (slow, fast, mixed).
Electrical specifications include a logic supply range of 4.5‑5.5 V, PWM turn‑off times of 18.2‑22.3 µs, and a thermal‑shutdown temperature of 165 °C. The devices are offered in a 16‑pin DIP (A3957SA) or a 24‑lead SOIC (A3957SLB) package, with detailed pin assignments for PWM control, sense, and output connections.
| Continuous Output Current | ±1.5 A |
|---|---|
| Output Voltage Rating | 50 V |
| Logic Supply Voltage Range | 4.5 V – 5.5 V |
| Thermal‑Shutdown Temperature | 165 °C |
| Package Options | 16‑pin DIP (A3957SA) or 24‑lead SOIC (A3957SLB) |
The driver can supply a continuous output current of up to ±1.5 A.
The A3957 supports three current‑decay modes: slow decay, fast decay, and mixed decay.
The recommended logic supply voltage is between 4.5 V and 5.5 V.
A3957SA is offered in a 16‑pin DIP package, while A3957SLB comes in a 24‑lead SOIC package.