ON Semiconductor Extends Current Range and Flexibility for Stepper Motor Designs

Both of the new mixed-signal ICs contain two embedded H-bridges that can drive two-phase stepper motors with sustained peak currents up to 400mA and maximum currents up to 800mA for short duration. Each also allows a host microcontroller to detect blocked rotor and end-of-run conditions without 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. This capability eliminates noise and vibration at end-stops and improves motion-control accuracy and reliability without additional components.

The 30512 contains a 5 volt regulator to supply both internal logic and up to 50mA for external components, such as a microprocessor. The 30512 also has watchdog logic circuitry to prevent an external microprocessor from “hanging up.”

“The AMIS-30511/512 devices extend our bipolar stepper motor micro-stepping driver family’s current drive range down to 400mA,” said Eric Wallentine, ON Semiconductor’s Industrial Product Marketing Manager. “By combining high-voltage analog circuitry and digital functionality on the same chip, these motor drivers let our customers design low cost, low component count motor driving systems for a wide variety of applications.”

Typical uses for the 30511/512 include security cameras, building and industrial automation, motor control, textile processing, process equipment, robotics, HVAC and base station control and status.