The A4255CA and A4255CLN microcontrollers make designing with step motors easy, inexpensive, and productive. A reference design technique is integral to the implementation of a system that includes the power circuitry, a low-cost, 8-bit, preprogrammed microcontroller and the other components needed to complete the control hardware. The A4255Cx eliminates the need for software development, expedites the product creation, and hastens the time to market. The reference design can be utilized directly or integrated into a larger printed wiring board. A further benefit is the compactness of the circuit layout. Power-driver output ratings presently available with these devices are 50 V and 1.5 A (with the A3955 or A3957). A similar device for 46 V and either 1.5 A (with the SLA7042M) or 3 A (with the SLA7044M) is planned. The reference design supports stepping formats that include full-step, half-step, quarter-step, eighth-step, and sixteenthstep (microstepping) increments for a two-phase stepping motor. The A4255CA is furnished in an 18-pin dual in-line plastic package for through-hole applications. The A4255CLN is furnished in a 20-lead wide-body, shrink-pitch, small-outline plastic package (SSOP) with gullwing leads for minimum area, surface-mount applications.