Efficient Power Conversion Corporation (EPC) announces the launch of the EPC91120, a high-performance three-phase brushless DC (BLDC) motor drive inverter optimised for humanoid robot joints. Featuring EPC’s EPC23102 ePower Stage IC, the EPC91120 delivers superior efficiency, high power density, and precise motion control in a compact 32mm-diameter footprint designed to integrate directly within robotic motor assemblies.
Compact, high-efficiency power for robotics
The EPC91120 evaluation board integrates three EPC23102 GaN monolithic half-bridge ICs with an on-board microcontroller, current and voltage sensing, magnetic encoder interface, and RS485 communication. The system operates from 15V to 55V DC, delivering up to 21A peak (15 ARMS) continuous current and 42A peak (30 ARMS) pulsed.
With a 100kHz PWM switching frequency and only 50ns dead time, the EPC91120 achieves exceptional efficiency and dynamic performance, ideal for humanoid robot joint motors and other high-precision motion applications. The board was specifically designed to fit the mechanical dimensions of the Unitree A1 robot motor, enabling direct evaluation in real-world robotic systems
Proven thermal and efficiency performance
Under natural convection cooling at 26°C ambient, the EPC91120 delivers 7 ARMS per phase without a heatsink and up to 15 ARMS when integrated into the humanoid joint motor casing as a heatsink. Experimental results demonstrate total system efficiencies exceeding 80% from DC input to mechanical output, validating the design for high-torque, low-weight robotic joints.
Advancing humanoid robotics with GaN integration
“The EPC91120 showcases tightly integrated GaN power that makes humanoid robots lighter, faster, and smarter by embedding high-density inverter electronics within each motor joint,” said Alex Lidow, CEO of EPC.
