Unipolar Stepper Motor

In unipolar stepper motors, stator windings share a common terminal; the free terminal of each winding is connected to a separate power switch and the current is allowed to flow in one direction through the motor windings. Diodes are used to clamp the voltage across the switches at turn-off. ST’s portfolio features a wide selection of power MOSFETs, diodes and microcontrollers to build a discrete implementation of a unipolar stepper motor driver.