ST Stepper Motor Control/Driver – ST L297/1, The L297 Stepper motor controller IC generates four phase drive signals for two phase bipolar and four phase unipolar step motors in microcomputer controlled applications. The motor can be driven in half step, normal and wave drive modes and on chip PWM chopper circuits permit switch-mode control of the current in the windings. A feature of this device is that it requires only clock, direction and mode input signals. L297/1 Stepper Motor Controller