The A3987 from Allegro MicroSystems is a Micro-Stepping Motor Driver IC that has been designed for precise control of bipolar stepper motors in full, half, quarter, and sixteenth-step modes. It requires an input voltage of up to 50 V and provides an output current of less than 1.5 A. It simplifies motor control with an integrated translator, necessitating only one pulse on the step input for one micro step, and eliminates the need for complex programming or phase sequence tables. It features a chopping control that automatically selects the current decay mode (slow or mixed), resulting in reduced audible motor noise, increased step accuracy, and lower power dissipation.

This motor driver uses a built-in fixed-off-time current regulator to ensure stable and regulated current output, thereby enhancing the overall performance of the stepper motor. It is an excellent choice for applications where a complex microprocessor is either unavailable or overloaded, offering a streamlined interface for efficient motor control. This motor driver is available in a surface-mount package that measures 7.80 x 6.40 x 1.20 mm.