It meets the needs of DIY users and professionals alike by combining advanced motor control, optimized power management, and versatile connectivity in a robust, high-performance package.
A growing interest in DIY projects has fueled the increasing popularity of portable power tools, driving demand for compact, high-performance, and cost-effective tools with advanced technology. Toolmakers continually innovate, integrating smart technology and efficient designs to enhance tool performance and user safety. As part of this evolution, brushless DC (BLDC) and permanent magnet synchronous motors (PMSM) are gaining traction due to their reduced friction, lower heat output, and longer lifespan. For manufacturers aiming to capture market share in the expanding power tools market, achieving high efficiency, compact size, and robust performance are key design priorities.
The portable power tool reference design by Microchip Technology leverages these high-performance BLDC/PMSM motors and integrates several features to enhance efficiency, battery life, and ease of use. With a wide input voltage range of 12.5V to 28V, the design supports up to a 6S battery setup, accommodating a maximum output power of 800W. It delivers 15A RMS continuously and up to 50A RMS for brief periods, allowing it to handle demanding applications while maintaining operational stability. To ensure precise motor control, the design uses low-side shunt resistors (1 mΩ) on each inverter phase for accurate current measurement. Additionally, a pulse-width modulation (PWM) frequency range of 12 kHz to 50 kHz, typically set at 20 kHz, allows optimized motor control and responsiveness. The inclusion of six low RDS(ON) N-Channel MOSFETs (around 1 mΩ) reduces energy loss, contributing to overall efficiency and minimizing heat generation.
The design further features robust connectivity and flexibility. Faston tab connectors facilitate secure connections for motor phases, while XT30-type connectors allow easy connection to various battery packs. The system is compatible with both sensored and sensorless motor control algorithms, providing versatility for different motor types and user preferences. A built-in PICkitâ„¢ debugger and programmer interface simplifies testing and development processes. Additional design features focus on monitoring and auxiliary functionality. An onboard MCP9700A temperature sensor provides real-time temperature monitoring, enabling users to maintain optimal operation and prevent overheating. Auxiliary connectors support customization, with options for I2C, UART, throttle control, trigger switches, and other programming or debugging needs.
At the core of the design is the dsPIC33CK64MP105, a 100 MHz, single-core, 16-bit digital signal controller (DSC) optimized for motor control and digital power applications. The MCP1722 dual output low dropout (LDO) regulator, known for its high-voltage tolerance and extended temperature range, powers the board, alongside the MCP1754S 16V high PSRR, 150mA LDO, which provides a stable 3.3V output. For precision sensing, the MCP6021, a 10 MHz rail-to-rail op amp, enhances the design’s ability to deliver reliable, high-quality operation under varied conditions. This reference design is a compact, efficient, and cost-effective solution for next-generation portable power tools.
Microchip has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
