Smart, high-power-density motor driver has 85V/10A power stage

May 12, 2015 // By Graham Prophet
STMicroelectronics’ powerSTEP driver delivers the advantages of compact motor-control design for applications at high power ratings. The fully integrated stepper-motor driver system-in-package offers power density of up to 500 W/cm², enabling cost-effective systems that deliver better performance and reliability without sacrificing flexibility or ruggedness.

As a complete 14 x 11 mm System-in-Package that requires only minimal external components, powerSTEP integrates both the control circuitry and a complete power stage for driving the motor. It is the first such highly integrated device suited to high-power applications up to 85V and 10A, significantly extending the scope of motor-control ICs used in industrial applications, high power lighting, surveillance systems, and home automation.

The power stage consists of eight MOSFETs with low internal resistance (RDS(ON)) of 16 mΩ typical. 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.

It can use ST’s voltage-mode motor control, which allows super-smooth and quiet motion with high position accuracy, or 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% of pc-board space compared to a design with discrete control and power-stage components. With comprehensive protection features built in, powerSTEP represents an extremely robust and reliable solution.

The POWERSTEP01 is in full production now, in the 14 x 11 mm VFQFN package priced from $4.50 (1000). The associated EVLPOWERSTEP01 evaluation board is also available to assist advanced application design.

ST; www.st.com