Stepper-motor chip controller features motion control logic

The precision, reliability, and high torque of stepper motors make them attractive to manufacturers for many applications. German-based Trinamic Microchips GmbH (Trinamic USA; Scottsdale, AZ) introduced the compact TMC 428 chip-controller.

"Together with small driver chips, it's possible to realize a motion control unit in the size range of a matchbox," says Jurgen Lenke of Trinamic USA.

Despite its size, the new chip controller contains motion control logic that lets it control up to three independent stepper motor axes. This built-in motion control software saves designers time otherwise spent programming microcontrollers or digital signal processors (DSPs).

The TMC 428, a motor, an 8-bit microcontroller (to provide the chip with position and speed information), and a driver, comprise a complete motion control system. Up to three drivers can be connected, cascaded with a serial peripheral interface (SPI), to also act as a simple but complete motion control system.

Trinamic reports that microstepping and situation-independent current control allow very precise and reliable positioning, while delivering a highly dynamic drive in applications where motors operate at defined velocities. For example, when used to control fiber-optic lighting, the host controller tells the TMC 428 to move an axis to a given position, and the chip will then take over such tasks as formulating a velocity-time curve, generating pulses for the steps, creating a switching pattern and current levels for the motor drivers, and querying limit switches.

To make it easier for potential users to test the TMC 428, Trinamic also offers a TMC 428 Evaluation Kit, which supports all features of the chip, and which can be controlled over the serial interface of a PC.

Additional Details...Trinamic USA, 29607 N. Hayden Rd., Scottsdale, AZ 85255; Tel: (480) 991-0000; www.trinamicusa.com ; or Enter 580.