Date: 03/05/2009

Low cost stepper motor controller ICs

LSI/CSI has released three new stepper motor controller ICs designated as LS8297, LS8297CT and LS8397. LSI/CSI says, these ICs are low cost replacement for L297 and also provide additional features not available in L297.

According to Pete Visconti, LSI's VP Sales and Marketing, all these devices offer half-step and full-step sequences in both normal drive and wave drive modes similar to the L297. In addition the LS8297CT and the LS8397 offer correction for the torque-ripple, not provided in L297 half-step sequence.
A power saving holding-torque mode is also available in LS8397 for maintaining the drivers at a reduced power level when the motor is not turning. Four phase outputs and two inhibit outputs are provided for driving external H-bridge drivers, allowing for the selection of a standard driver, such as the popular L298 or an application specific custom driver.
An external reference voltage, in conjunction with the winding current sense voltages, regulate the 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.

LS8297 and LS8297CT features include:
1. Pin-for-pin cost effective replacement for L297
2. Half and full step sequences
3. Normal-drive/wave-drive
4. Torque ripple correction in LS8297CT
5. PWM chopper circuit for motor current control
6. Inputs for step, forward/reverse, reset and output blanking control
7. Supply current < 400uA
8. Supply voltage: 4.5V to 7V
9. LS8397 includes all of the above plus a mode for reduced power holding torque.
10. LS8297 and LS8297CT are available in available in 20-pin DIP, SOIC and TSSOP packages
11. LS8397 is available in 24-pin DIP, SOIC and TSSOP packages

For further details visit www.lsicsi.com