A3981KLPTR-T

The A3981KLPTR-T from Allegro Microsystems is a flexible, single-chip microstepping motor driver designed for bipolar stepper motors. It operates at voltages up to 28 V and provides a peak motor current of ±1.4 A. The device supports full, half, quarter, and sixteenth-step modes, controllable via simple Step and Direction inputs or a SPI-compatible serial interface.

The integrated translator simplifies operation, while the SPI interface allows for programming of features and reading diagnostic information. The current regulator supports fixed off-time or fixed frequency PWM with various decay modes to reduce motor noise and improve step accuracy. Synchronous rectification is employed in the DMOS full bridge to enhance power dissipation.

Protection features include short-circuit and open-load diagnostics, crossover-current protection, and chip-level thermal shutdown, overvoltage, and undervoltage lockout. It also includes hot and cold thermal warnings and stall detect features. The A3981 is supplied in a 28-pin TSSOP power package with an exposed thermal pad (LP package).

This driver is suitable for automotive applications such as engine management and headlamp positioning, where precise motor control and integrated diagnostics are required.