International Rectifier’s new motion control ICs eliminate programming tasks

A drumbeat often heard today is shorter time-to-market for product development. Two new digital control ICs recently introduced by International Rectifier (IR) promise to do just that by easing the configuration of motion control algorithms for permanent magnet (pm) and ac induction motors—along with their position feedback devices.

By Control Engineering Staff December 17, 2003
IR’s new IRMCK201 digital motion control IC (available now) sells for $13.85 each, while IRMCK203 (available in Jan. 2004) is priced at $19.85 each, in 10k-unit quantities. additional IC types are coming.

A drumbeat often heard today is shorter time-to-market for product development. Two new digital control ICs recently introduced by International Rectifier (IR) promise to do just that by easing the configuration of motion control algorithms for permanent magnet (pm) and ac induction motors—along with their position feedback devices. IRMCK201 and IRMCK203 are part of IR’s iMotion expanding integrated design platform for motion control.
These single-chip ICs incorporate a Motion Control Engine (MCE) reportedly unique to the point of eliminating software programming. This contrasts with traditional motor drive controls that rely on complex digital signal processors or microprocessor control units. Motion-control products developed with IRMCK201 and IRMCK203 use commands simplified to menu-driven selections that streamline the design cycle. To configure the ICs, users just need to set-up registers, explains Toshio Takahashi, director of engineering for IR’s Digital Control IC Design Center. “IR has mapped various switches into these chips to allow easy configuration of parameters, such as torque or speed mode of the motor, feedback type, etc.,” he says.

IRMCK201, intended for brushless pm servo and induction motors, features encoder feedback-based closed-loop current and velocity control. Space vector PWM (pulse-width modulation) with-dead time insertion transfers information efficiently to and from the IC to power devices with low loss and less noise. Typical markets include semiconductor wafer-handling equipment, pick-and-place machines, high-speed labeling machines, and other precision motion-control applications. IRMCK203 is dedicated to brushless servo motors only and sensorless (encoderless) drives for higher speed applications. This IC accommodates ultra high-speed (100,000 rpm) and wide speed range (>20:1) designs; example applications are machine tool spindles, robots, and dental drills. Sensorless feedback circuits combine with low-loss, space-vector PWM and special motor starting algorithm to minimize torque ripple.

IRMCK201 and IRMCK203 offer maximum current control update rate of 60 kHz. These ICs include a fast serial peripheral interface (SPI) port for connecting various external devices via two data lines and two control lines. Maximum SPI speed is 6 MHz. RS-232/-422/-485 communication is supported.

—Frank J. Bartos, executive editor, Control Engineering, fbartos@reedbusiness.com