Smart motor driver boosts industrial automation

STMicroelectronics debuted its powerSTEP driver, an integrated stepper-motor driver system-in-package that offers up to 500W/cm2 power density at the PCIM Europe 2015.

The 14mm x 11mm system-in-package integrates control circuitry and complete power stage for driving the motor. It powers applications requiring up to 10A and 85V, such as in motor-control ICs used in industrial applications like automated machinery, industrial sewing machines, stage lighting, surveillance systems and home automation.

The power stage consists of eight MOSFETs with low internal resistance (R_DS(ON)) of just 16mΩ typical, which maximises energy efficiency and minimises heat dissipation to simplify thermal management. The integrated control IC includes an intelligent motion engine to perform calculations normally executed in the main system microcontroller, which gives engineers extra freedom when selecting the microcontroller, and helps simplify software and firmware design.

Users benefit from the flexibility to use ST's patented voltage-mode motor control, which allows super-smooth and quiet motion with high position accuracy, or to use an advanced current-mode with predictive control and adaptive decay algorithm when required. Resolution of 128 microsteps per step is comparable with the best stepper-motor controllers being used today.

An industry-standard SPI connection to the host allows convenient programming, and current-sense management and sensorless stall detection. By requiring only minimal external components, powerSTEP saves up to 50 per cent of PC-board space compared to designs with discrete control and power-stage components.

The POWERSTEP01 is in full production now, in a 14mm x 11mm VFQFN package priced from $4.50 for orders of 1,000 pieces. The EVLPOWERSTEP01 evaluation board is also available to assist advanced application design.