The UC3717 has been designed to control and drive the current in one winding of a bipolar stepper motor. The circuit consists of an LSTTL-compatible logic input, a current sensor, a monostable and an output stage with built-in protection diodes. The UC3717A is an improved version of the UC3717. It has been modified to supply higher winding current, more reliable thermal protection, and improved efficiency by providing integrated bootstrap circuitry to lower recirculation saturation voltages. The circuit is equipped with a thermal shutdown function, which will limit the junction temperature by reducing the output current. It should be noted however, that a short circuit of the output is not permitted.
Herein the following file, you will find detail information regarding Stepper Motor Drive Circuit using UC3717A features and description, block diagram, circuit diagram, electrical characteristics, functional description (output stage, phase polarity input, current control, performance consideration, overload protection) mounting instruction and applications.
Get more info of Stepper Motor Drive Circuit using UC3717A here – http://focus.ti.com/lit/ds/symlink/uc3717a.pdf – free download PDF file.