AMI Intrdouces Sensorless Single-Chip Driver ICs for Stepper Motors

AMI Semiconductor (NASDAQ:AMIS), a leading designer and manufacturer of state-of-the-art mixed-signal and digital products for the automotive, medical, industrial, and military/aerospace markets, has announced two new single-chip stepper motor driver ICs that will significantly reduce component count and bill of materials (BOM) cost in dynamic motion applications. The AMIS-30521 and AMIS-30522 allow engineers to eliminate the need for switches, Hall sensors, flyback diodes, and many passive components in applications ranging from headlamp positioning systems and surveillance cameras to automated pick-and-place systems, vending machines, textile machines, stage lights, and much more.

Each of the new mixed-signal ICs features two embedded H-bridges capable of driving two-phase stepper motors with currents up to 1600mA. Speed and load angle outputs allow a host microcontroller to detect blocked rotor and end-of-run conditions without the need for additional switches, Hall sensors or optical encoders. In addition to stall detection, these functions allow the designer to program the microcontroller to calculate rotor position, and to dynamically adjust current or speed as required to prevent step loss. As a result, noise and vibration at end-stops can be eliminated and motion control accuracy and reliability improved without additional components.

Each new device is designed as a companion chip to be used in conjunction with a host microcontroller or DSP. Each device offers an SPI interface and can take full control of the translation of NXT ‘next-step’ input pulses to deliver the appropriate PWM outputs to the motor coils. In addition, the AMIS-30522 incorporates a 50mA voltage regulator and watchdog for the external microcontroller. Both devices offer micro-stepping from full step down to 1/32, including compensated and non-compensated half steps. Embedded current sensing functionality further reduces component count by eliminating requirements for external current sense resistors.

“A growing number of processing, automotive, security, and building automation applications rely on stepper motors to deliver dynamic motion,” said Guido Remmerie, manager, worldwide industrial ASSPs at AMIS. “These new miniature stepper motor drivers allow designers to quickly and easily implement dynamic motion applications with minimum component count and the lowest possible BOM cost.”

The new device is currently available in a NQFP package option with exposed pad, offering profiles of under 1mm and footprints of just 7mm x 7mm. Despite their small size, the devices offer a comprehensive set of additional features including diagnostics and protection against overcurrent, under- and over-voltage, open or shorted coils, and over-temperature conditions. In addition to saving board space, the small package size also facilitates direct mounting onto the stepper motor for further space saving and reduced circuit complexity.

Unit pricing for the AMIS-3052x devices is $4.65 in volumes above 1000 (for US). Unit pricing for the AMIS-3052x devices is €3,66 in volumes above 1000 (for EU).

About AMI Semiconductor
AMI Semiconductor (AMIS) is a leader in the design and manufacture of silicon solutions for the real world. As a widely recognized innovator in state-of-the-art mixed-signal and digital products, AMIS is committed to providing customers in the automotive, medical, industrial, mil/aero, and communication markets with the optimal value, quickest time-to-market semiconductor solutions. AMI Semiconductor operates globally with headquarters in Pocatello, Idaho, European corporate offices in Oudenaarde, Belgium, and a network of sales and design centers located in the key markets of the North America, Europe and the Asia Pacific region.