Shrink Motor Drives for eBikes, Robots, and Drones with 100V Gallium Nitride (GaN) FETs from EPC

The EPC9194 GaN-based inverter reference design significantly enhances motor drive system efficiency, range, and torque, while more than doubling power per weight. The inverter’s extremely compact size allows seamless integration into the motor housing resulting in the lowest electromagnetic interference (EMI,) highest density, and lowest weight.

EL SEGUNDO, Calif.— October 2023 — EPC announces the availability of the EPC9194, a 3-phase BLDC motor drive inverter reference design board. It operates from an input supply voltage range of 14V to 60V and delivers up to 60 A_pk (40 A_RMS) output current. This voltage range and power level make the solution ideal for a variety of 3-Phase BLDC motor drives including eBikes, eScooters, drones, robots, and DC servo motors.

The EPC9194 demonstration board features six (6) EPC2302 100V eGaN FETs in a 3 mm x 5 mm QFN package.  The board’s size is only 130 mm x 100 mm (including the connector). The EPC2302 eGaN FET offers an incredibly small R_DS(on), of just 1.8 mOhm, combined with very small Q_G, Q_GD, and Q_OSS parameters for reduced conduction and switching losses. The package is a thermally enhanced QFN with an exposed top for enhanced heat dissipation to the heatsink and wettable flanks for easy inspections.

The estimated total power loss with six EPC2302’s at 20A_RMS and with 100kHz PWM frequency is half that of a Si MOSFET solution with the same R_DS(on) operating at 16kHz PWM frequency. The 100kHz PWM frequency enables a quasi-pure sinusoidal current, reducing vibration and distortion in the motor and resulting in about 7% higher motor system efficiency. Additionally, 100kHz PWM frequency allows for the reduction of the input filter and the elimination or reduction of electrolytic capacitors.

The EPC9194 incorporates all the critical circuit functions required to support a complete motor drive inverter, including gate drivers, regulated auxiliary power rails for housekeeping supplies, voltage, and temperature sense, accurate current sense, and protection functions.

With a 48V input and 100kHz PWM frequency, the board can deliver 20A_RMS steady state without a heatsink with a temperature rise of 60 °C, and more than 30A_RMS with a heatsink.

The EPC9194 is compatible with various controllers from different manufacturers allowing for quick development and reduced design cycle times. EPC offers control interface boards (EPC9147X) to operate this inverter reference design with the many common BLDC motors. The EPC9194KIT includes the EPC9194 evaluation board and a controller board that allows to easy interface of the board with a microcontroller design kit:

EPC9147A controller board to interface to popular Microchip microcontrollers

EPC9147C controller board to interface to popular ST microcontrollers

EPC9147B controller board to interface to popular TI microcontrollers

EPC9147E controller board to interface to generic microcontrollers

“Designers can use EPC GaN FETs to make lighter-weight and more efficient battery-operated motor drives for a wide variety of e-mobility and robotic applications”, said Alex Lidow, CEO of EPC. “GaN enables motor systems that are smaller, lighter, quieter, more powerful, and more precise while improving EMI, reducing the need for EMI filtering and capacitors, and eliminating electrolytic capacitors and input filter inductors.”