ST’s Plug-&-Play Prototype Boards for controlling 3-phase brushless motors powered by up to 56V Li-ion batteries
STMicroelectronics simplifies development of Cordless Power Tools with Plug-and-Play STSPIN32 Prototype Boards. Aiding the development of state-of-the-art cordless home and garden power tools, the company introduces two new plug-and-play boards the STEVAL-PTOOL1V1 and STEVAL-PTOOL2V1 for controlling 3-phase brushless motors powered by up to 56V Li-ion batteries.
Based on ST’s highly integrated STSPIN32 motor-control Systems-in-Package, the STEVAL-PTOOL1V1 and STEVAL-PTOOL2V1 evaluation boards fulfil key requirements of power tools including small dimensions and low standby current. Firmware is supplied for six-step motor commutation using Hall-effect rotor-position sensing, which ensures low torque ripple and optimum power efficiency.
The STEVAL-PTOOL1V1 for equipment powered by Li-ion battery packs from two cells (7.4V) to six cells (22.2V) has a 70mm x 30mm footprint and delivers up to 15A continuous current. Standby current is less than 1µA. At the heart of the board is the STSPIN32F0B motor controller, which contains an STM32F0 microcontroller, 3-phase half-bridge gate driver, 12V and 3.3V voltage regulators, an op-amp for current sensing and power-stage protection features such as programmable over-current protection (OCP), cross-conduction prevention and under-voltage lockout (UVLO). The STEVAL-PTOOL1V1 power stage features the ST Power MOSFET N-channel 60V STripFET F7 technology.
The STEVAL-PTOOL2V1, for battery sizes from eight cells (29.6V) to 15 cells (55.5V), can deliver up to 19A continuous current. It is controlled by ST’s STSPIN32F0252 motor controller, which contains a 3-phase 250V gate driver, an STM32F0 microcontroller, and a comparator designed to offer very fast and flexible OCP. The STSPIN32F0252’s rugged design allows output pins to resist below-ground spikes down to -120V, which enhances the reliability of power tools. Featuring on-board bus voltage sensing, the STEVAL-PTOOL2V1 board measures 77mm x 54mm. The power stage features the ST Power MOSFET N-channel, 80V, STripFET F7 technology.
Both boards provide a potentiometer for speed variation, inputs for trigger and rotation-direction setting, thermal shutdown, and protection against reverse biasing of power-stage outputs. They are supplied with a heatsink already mounted.
In addition to cordless tools, the boards can be used in any battery-operated applications that utilize brushless 3-phase motors with single-shunt control.
The STEVAL-PTOOL1V1, priced at $41.00, and STEVAL-PTOOL2V1, $69.00, are available now. The STSW-PTOOL1 firmware for STEVAL-PTOOL1V1 and STSW-PTOOL2 for STEVAL-PTOOL2V1 can be downloaded free of charge from www.st.com