The LS8297, LS8297CT, and LS8397 stepper motor-controller ICs from LSI Computer Systems Inc. are designed to replace the L297 in all applications while providing additional features. They offer half-step and full-step sequences in both normal drive and wave-drive modes similar to the L297. In addition, the LS8297CT and LS8397 offer correction for the torque-ripple, not provided in the L297 half-step sequence. A power-saving holding-torque mode also is available in the LS8397 for maintaining the drivers at a reduced power level when the motor isn’t turning.
Four phase outputs and two inhibit outputs are provided for driving external H-bridge drivers, allowing for the selection of a standard driver like the L298 or an application-specific custom driver. An external reference voltage, in conjunction with the winding current-sense voltages, regulates the pulse-width modulation (PWM) duty cycles of the driver outputs. One of two decay modes, fast-decay and slow-decay, can be selected to suit the characteristics of the motor winding. The ICs operate from a supply current of less than 400 µA and a supply voltage of 4.5 to 7 V.
The LS8297 and LS8297CT are available in a 20-pin dual-inline package (DIP), small-outline IC (SOIC) package, and thin-shrink small-outline package (TSSOP). The LS8397 is available in a 24-pin DIP, SOIC, and TSSOP. The LS8297 costs $2.00 and the LS8297CT costs $2.25, in any package, in 1000-unit quantities. The SOIC and TSSOP LS8397 costs $2.50 and the DIP version costs $2.60, both in 1000-unit quantities.
LSI Computer Systems Inc.