Efficient Power Conversion Corporation (EPC) has announced the release of the EPC91120, a high-performance 3-phase brushless DC (BLDC) motor drive inverter designed specifically for integration into humanoid robot joints.
The EPC91120 leverages EPC’s EPC23102 ePower™ Stage IC to deliver superior efficiency, high power density, and precise motion control in a compact 32 mm-diameter form factor. The board is optimized to fit directly into robotic motor assemblies, including compatibility with the mechanical dimensions of the Unitree A1 robot motor.
The EPC91120 evaluation board incorporates three EPC23102 monolithic GaN half-bridge ICs, along with an onboard microcontroller, current and voltage sensing, a magnetic encoder interface, and RS485 communication. Operating from 15 V to 55 V DC, the system supports up to 21 A peak (15 ARMS) continuous current and 42 A peak (30 ARMS) in pulsed operation.
With a 100 kHz PWM switching frequency and minimal dead time of just 50 nanoseconds, the EPC91120 delivers exceptional dynamic performance and system efficiency. These characteristics make it well suited for high-precision motion control in humanoid robotics and other advanced mechatronic applications.
Thermal and efficiency testing confirms strong performance under real-world conditions. Under natural convection cooling at 26°C ambient, the system achieves 7 ARMS per phase without a heatsink. When mounted within a humanoid joint motor casing used as a thermal sink, it can deliver up to 15 ARMS. Overall system efficiency exceeds 80 percent from DC input to mechanical output, validating the design’s suitability for high-torque, lightweight robotic joints.
“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.
The EPC91120 demonstrates the benefits of GaN integration in next-generation robotics, enabling compact, efficient, and scalable motor control for advanced autonomous systems.
Original – Efficient Power Conversion