New Programmable Motor Controller from STMicroelectronics Aims for Efficient Battery-Powered Devices

October 22, 2017 by Heather Hamilton-Post

Small batteries increase the need for low power use, efficient design. In this News Brief, we take a look at the STSPIN32F0A programmable motor controller from ST Micro.

Small batteries increase the need for low power use, efficient design. In this News Brief, we take a look at the STSPIN32F0A programmable motor controller from ST Micro.

There’s a drive for more efficient products across most industries, but particularly in technology. With the push toward machine learning, smaller and faster products, and devices that accomplish multiple tasks at once, efficiency is driving the industry.

Perhaps nowhere is this more important than in circuit design, especially for battery-powered devices.

An Efficiency Solution from STMicro

STMicroelectronics recently released a motor driver with an embedded 32-bit MCU, designed to simplify motion control for battery-operated appliances and even robots.

The press release advertises fully-integrated gate drivers for three external MOSFET half-bridges, an STM32F0 microcontroller, and 3.3V DC/DC switching converter plus 12 LDO. Designed to provide designers with flexible motor control options, it is lightweight and compact with a 48MHz microcontroller and 32Kbyte on-chip Flash. The STSPIN32F0A runs motor control algorithms like 6-step sensorless, field-oriented control/position sensed control, and user application.

The product has an extended operating voltage range and runs on small batteries, making it useful in mobile robots, gimbals, drones, power tools, server cooling fans, 3D printers, and portable appliances.




Marketed toward developers, STMicro proclaims 16 programmable I/O pins and microcontroller peripherals that save CPU involvement to handle motor back-EMF or position/Hall-sensor feedback, allowing for precise control down to almost zero rotor speed, including a 12-bit and 9-channel ADC and three operational amplifiers.

STMicro really wants users to know that it is designer-friendly and customizable--including five all-purpose timers and I2C, UART, and SPI interfaces with access to the bootloader to upgrade firmware over the air,gate-driver IC delivers up to 600mA per channel, integrated bootstrap diodes, built-in protection, and integrated 3.3V DC/DC converter.

The motor driver connects to ST’s development ecosystem and approved third-party resources within the STM32 Partner Program, and is currently available at $1.605 for 1000 pieces.

Purdue Works Toward Inverter Efficiency in Automotive Applications

ST Micro's new components are part of a larger trend towards efficiency-focused design. Battery-powered devices are increasingly important, from phones to vehicles.

In electric vehicles, inverter improvements are creating opportunities for more efficient motor drive systems. Researchers from Purdue University recently designed an inverter used to convert direct current electricity from a battery, fuel cell, or another source into alternating current to power a motor. More conventional technologies require passive filters that keep motors from experiencing the side effects from high voltage edge rates, though they experience power loss, higher weight, and overall volume.

The research team developed a circuit which controls the dv/dt via soft-switching, eliminating the filter requirement and reducing power loss. The team also says that the dv/dt is reduced at a much lower cost than passive filters provide.

Purdue’s circuit augments an inverter which is only active during voltage transitions with an auxiliary circuit, which is only for a short period of time. The currents passing through are small, allowing for smaller components and lower power loss. Soft-switching also eliminates the loss in the inverter main circuit, making it a more efficient choice.

Currently, the research team is working to prove that it is commercially viable.