Efficient Power Conversion (EPC) has introduced the EPC91132, a compact three-phase brushless DC (BLDC) motor drive inverter reference design built around the company’s EPC33110 gallium nitride (GaN) three-phase power module. The new platform is designed to support next-generation motion control applications, including humanoid robot joints, robotic hands and wrists, and drone propulsion systems.
The EPC91132 features an ultra-compact design with a diameter of just 23 mm, making it suitable for space-constrained motor drive applications. At the core of the reference design is the EPC33110 GaN module, which leverages EPC’s monolithic GaN integrated circuit technology. The module integrates three half-bridges, gate drivers, bootstrap circuitry, and level shifters within a compact 6 mm × 6.5 mm QFN package.
Powered from a single 5 V supply, the EPC33110 supports operating voltages up to 80 V and offers a typical on-resistance of 11.7 mΩ. The module is compatible with both 3.3 V and 5 V logic inputs, providing flexibility for a variety of control architectures.
As robotic and drone systems continue to demand smaller, lighter, and more efficient power electronics, GaN technology is increasingly being adopted for motor drive applications. The ability to operate at switching frequencies above 100 kHz while minimizing both conduction and switching losses enables improved efficiency, faster dynamic response, higher control bandwidth, and reduced passive component size.
The EPC91132 supports a wide input voltage range from 10 V to 60 V DC and integrates all key functions required for a complete inverter system. These include an onboard microcontroller, regulated power supplies, DC bus voltage sensing, current sensing with integrated overcurrent protection, and a magnetic encoder for rotor position and speed control.
The monolithic architecture of the EPC33110 eliminates the need for discrete gate drivers, significantly reducing component count while simplifying PCB design and accelerating development. The platform can be programmed through a dedicated connector and supports real-time monitoring via an RS-485 communication interface.
To accommodate different application requirements, EPC designed the board with a flexible breakout-ring structure. When the outer ring is removed, the board maintains its 23 mm diameter, allowing direct integration into compact motor systems such as the Vertiq 23-06 drone motor platform.
Performance testing demonstrated that the EPC33110 module can deliver continuous phase currents of up to 11 ARMS in humanoid robotic joint applications operating at 48 V and switching frequencies up to 100 kHz. In drone motor evaluations, the system exhibited strong thermal performance, with only minimal temperature rise observed under airflow generated by the propeller.
According to EPC, the EPC91132 demonstrates how monolithic GaN integration can simplify inverter design while providing the switching speed, power density, efficiency, and thermal performance required by next-generation robotic and aerial mobility systems.
The new reference design is intended to provide engineers with a compact and highly integrated development platform for evaluating GaN-based motor drive architectures in advanced motion-control applications.
Original – Efficient Power Conversion