Compact Integrated GaN Drive Built for Robots, Drones
Efficient Power Conversion’s (EPC) EPC91132 is a compact 3-phase BLDC motor-drive inverter reference design based on the EPC33110 GaN three-phase module. It’s intended for small motor drives used in humanoid wrists and hands and in drones.
The EPC33110 GaN module integrates three half-bridges, gate drivers, bootstrap circuitry, and level shifters in a small 6- × 6.5-mm QFN package. The module can be powered by a single 5-V power supply of up to 80 V with typical on-resistance of 11.7 mΩ and support for 3.3- or 5-V logic inputs.
It provides a continuous current of 11 A RMS per phase for humanoid robotic joint applications operating at 48 V and switching frequency up to 100 kHz. In drone motor testing, the system demonstrated excellent thermal performance with minimal temperature increase under the airflow from the propeller.
The EPC91132 driver reference design has a wide 10- to 60-V DC input range and includes all of the key functions needed for an inverter: microcontroller, regulated power supplies, DC bus voltage sensing, current sensing with embedded overcurrent protection, and onboard magnetic encoder for rotor position and speed control.
The reference’s monolithic GaN architecture eliminates the need for discrete gate drivers and significantly reduces component count, simplifying PCB layout The platform is programmable through a dedicated connector and can be monitored in real-time through its RS-485 port.
The board has been designed with a flexible breakout-ring concept to support various form factors, such as housings for small drone motors like the Vertiq 23-06 platform.
Complete design support files, including schematics, bill of materials (BOM), and Gerber files, are downloadable from the EPC91132 product page.
The EPC91132 evaluation board is priced at $406.25. Reference design boards and devices are available for immediate delivery from DigiKey and Mouser.
About the Author
Lee Goldberg
Contributing Editor
Lee is the author of the popular PowerBites series.
Lee Goldberg is a self-identified “Recovering Engineer,” Maker/Hacker, Green-Tech Maven, Aviator, Gadfly, and Geek Dad. He spent the first 18 years of his career helping design microprocessors, embedded systems, renewable energy applications, and the occasional interplanetary spacecraft. After trading his ‘scope and soldering iron for a keyboard and a second career as a tech journalist, he’s spent the next two decades at several print and online engineering publications.
Lee’s current focus is power electronics, especially the technologies involved with energy efficiency, energy management, and renewable energy. This dovetails with his coverage of sustainable technologies and various environmental and social issues within the engineering community that he began in 1996. Lee also covers 3D printers, open-source hardware, and other Maker/Hacker technologies.
Lee holds a BSEE in Electrical Engineering from Thomas Edison College, and participated in a colloquium on technology, society, and the environment at Goddard College’s Institute for Social Ecology. His book, “Green Electronics/Green Bottom Line - A Commonsense Guide To Environmentally Responsible Engineering and Management,” was published by Newnes Press.
Lee, his wife Catherine, and his daughter Anwyn currently reside in the outskirts of Princeton N.J., where they masquerade as a typical suburban family.