LSI/CSI Releases New Precision Stepper Motor Controller For Bipolar & Unipolar Motors

LSI Computer Systems, Inc. (LSI/CSI) announced the availability of its new high performance stepper motor controller integrated circuit, designated the LS7290. According to Pete Visconti, VP Sales and Marketing, "A huge advantage for our customers is that the low cost LS7290 can replace the expensive L297 in most applications while providing more programmable micro-steps. This new IC is capable of a large selection of step sizes ranging between full and 1/32 step."

The LS7290 is designed to control two-phase bipolar stepper motors or four-phase unipolar stepper motors with minimum burden on the resources of a host micro-controller. For bipolar motors, the LS7290 interfaces with an external dual full bridge driver such as the L298, which contains a pair of H- bridges driven by the LS7290 PWM and phase control outputs. The H-bridges allow for the selection of wide range of motor sizes. For unipolar motors, the LS7290 PWM and phase control outputs interface with four AND gates driving four NMOS driver transistors.

Inputs to the LS7290 are available to control the step size, step command, motor direction, over-current sense, over-current threshold and inter-step phase drive blanking delays. The programmable inter-step blanking delays allow for delay selection to suit a specific motor resulting in reduced audible motor noise, increased step accuracy, and reduced power dissipation. The basic timing clock can be supplied either from the built-in oscillator or from the system clock.

The LS7290 is available in 24-pin DIP, SOIC and TSSOP packages. Pricing at 1,000 pieces is $1.15.