Stepper-motor driver boosts integration and saves sensors

A new family of micro-stepping drivers from ON Semiconductor features speed and load-angle outputs to aid calibration, support stall detection, and eliminate the need for external sensors in bipolar stepper-motor applications.

By supporting micro-stepping, the AMIS-30521 and AMIS-30522 enable engineers to optimise speeds, audible noise, and step-loss due to resonance phenomena. The IC can be interfaced via I/O pins and the SPI bus to an external MCU. They also contain a current-translation table and take the next micro-step on every rising (or falling) edge of the signal on the NXT input pin. A motion-direction input pin is also included.

The devices provide speed and load-angle output signals to stall-detection algorithms and control loops running on the MCU. This allows adjustment of torque and speed, and also enables semi-closed-loop operation when approaching the mechanical end-stops, without the need for an external sensor.

The AMIS-3052x family uses a proprietary PWM algorithm for reliable current control, and combines both high-voltage analogue circuitry and digital functionality on the same IC. The devices comply with automotive requirements, and are available in the compact, thermally-enhanced 7mm x 7mm NQFP-32 package featuring an exposed pad.

 

FEATURES Dual H-bridge for two-phase stepper motors Programmable peak-currents: ≤1.6A in 32 steps On-chip current translator Active flyback diodes Programmable voltage slopes and PWM frequencies

APPLICATIONS Building automation Automotive positioning and control systems Intelligent-positioning systems Dose pumps Vending machines Pick-and-place machines Sewing, textiles and weaving

 

 

ON Semiconductor / AMIS-3052x