ST Releases New Reference Board for High-Current Brushless Motors

STMicroelectronics recently released a new reference board, the ELDRIVE101-HPD, which combines an STDrive101 three-phase, triple half-bridge gate driver with an Arm Cortex M0+ STM32G071KB microcontroller. ST designed the board to drive 750 W brushless DC motors (BLDCs). The design uses six STL220N6F7 60-V STripFET F7 MOSFETs to drive BLDC motors from 18 V to 52 V at up to 15 A. The N-channel MOSFETs have a low RDS, at 1.2 mΩ, and the entire system has a sleep mode power draw of less than 1 uA.

EVLDRIVE101-HPD 750W BLDC motor drive. 

Brushless DC motors are electrically and audibly quieter than their brushed companions. They feature longer service lives and more reliable speed control. Their primary disadvantage is that they require electronic control. While a brushed motor requires little more than a DC power source and a switch, BLDCs require complex drive circuitry. The new reference design from ST removes much of the complexity by offering a complete circuit in a size and configuration that is ready to use out of the box.

At 50 mm (less than 2”) in diameter, the motor drive board can fit into many form factors that were previously out of reach for high-powered BLDC motors. It is designed for small battery-powered devices like hair dryers, power tools, and fans. Its small size and high power also make it useful for household robots and personal drones. Outside the home, it enables more compact industrial equipment such as pumps and process automation equipment.

Key Product Specifications

The full-featured three-phase BLDC drive starts with a 32-bit STM32G071KB Arm Cortex M0+ microcontroller. The STM32G071KB operates at up to 64 MHz and offers 36 Kbytes of SRAM and 128 Kbytes of Flash. The board has an STDC14 debug connector and is compatible with single-wire debug (SWD). Users can update the firmware directly through an internal UART.

The STDRIVE101 three-phase, single-chip gate driver for N-channel MOSFETs configures as three half bridges. Each driver can sink/source 600 mA. The chip operates at voltages from 5.5 V to 75 V and has an integrated low dropout (LDO) voltage regulator and bootstrap circuitry to drive both the low- and high-side gate drivers. It also has configurable drain-to-source voltage (VDS) monitoring and overdriver protection built in.

EVLDRIVE101-HPD 750W BLDC motor drive, back side.

The six STL220N6F7 power MOSFETs have an extremely low RDS, at 1.2 mΩ, and are driven to 60 V in the reference design to deliver up to 750 W. The STDRIVE101 and external ST TSV991ILT CMOS op amps accomplish current sensing. The board also features an external on/off trigger with very low standby current, overcurrent and thermal shutdown protection, undervoltage lockout (UVLU), and back EMF (BEMF) current sensing and limiting. It also includes a connector for Hall-effect sensors and encoder.

All-ST Silicon

All of the active silicon components in the drive come from ST, including the microcontroller (MCU), three-phase, triple half-bridge driver, MOSFETs, Schottky diodes, and power supply chips. This ensures that the entire circuit was designed by the people most familiar with all components. This will reduce supplier count when it comes time for OEMs to mass produce the board or a derivative. Users can download Gerber files and a bill of materials (BOM) from ST's site. As of this writing, the schematic is available in PDF form in the EVLDRIVE101-HPD data sheet. For further development support, ST offers the X-CUBE-MCSDK STM32 motor control software development kit for download.

Overview of the ELDRIVE101-HPD and Related Products

The ELDRIVE101-HPD is a high-performance reference board from STMicroelectronics, designed to drive 750 W brushless DC (BLDC) motors. It integrates an STDrive101 three-phase, triple half-bridge gate driver with an Arm Cortex M0+ STM32G071KB microcontroller. This combination delivers efficient and precise motor control, ideal for applications requiring high power and compact size, such as hair dryers, power tools, household robots, and personal drones.

BLDC motors, known for their quiet operation and reliable speed control, require sophisticated electronic control circuits. The ELDRIVE101-HPD simplifies this complexity by providing a ready-to-use solution with integrated components, including six STL220N6F7 60-V STripFET F7 MOSFETs. These MOSFETs offer low RDS(on) and support efficient power delivery from 18 V to 52 V at currents up to 15 A. The system's low standby power consumption makes it suitable for battery-powered applications.

This reference board falls into the broader category of motor control solutions, which include various products such as gate drivers, microcontrollers, MOSFETs, and development kits. STMicroelectronics' portfolio ensures seamless integration and optimal performance, providing a comprehensive ecosystem for designers. The all-ST silicon design of the ELDRIVE101-HPD ensures compatibility and ease of sourcing for OEMs, with additional support available through the X-CUBE-MCSDK STM32 motor control software development kit.