EPC's new 100 V GaN FETs help enable smaller motor drivers

EPC announced the introduction of the three-phase BLDC Motor Drive Inverter Reference Design (EPC9194). It has an operating input power supply voltage range of 14V to 60V and can provide output current of up to 60 Apk(40 ARMS). This voltage range and power make the solution ideal for use in a variety of three-phase BLDC motor drives, including e-bikes, e-scooters, drones, robots, and DC servo motors.

The EPC9194 demo board features six 100 V eGaN FETs (EPC2302) in a 3mm x 5mm QFN package. The size of the board is only 130 mm x 100 mm (including connectors). The EPC2302 eGaN FET has a very small RDS(on) (only 1.8 mOhm) and very small QG, QGD, and QOSS parameters, resulting in reduced conduction and switching losses. The package comes in a heat-resistant enhanced QFN package with a bare top for efficient heat dissipation to the radiator and wettable sides for easy inspection.

Compared to a Si MOSFEt-based solution with the same RDS(on) operating at 16 kHz PWM frequency, this reference design with six EPC2302s reduces the estimated total power consumption at 20 ARMS and 100 kHz PWM frequency by half. The 100 kHz PWM frequency enables quasi-pure sinusoidal current, reduces vibration and distortion in the motor, and improves the efficiency of the motor system by approximately 7%. In addition, the 100 kHz PWM frequency can reduce the input filter and eliminate/reduce electrolytic capacitors.

The EPC9194 integrates all of the key circuit functions needed to support the entire motor drive inverter, including gate drivers, regulated auxiliary power rails to assist in power management, voltage and temperature sensing, precise current sensing, and protection.

At 48 V input voltage and 100 kHz PWM frequency, the board can handle 20 ARMS of current under steady state conditions with a temperature rise of 60°C without heat sink. With a radiator, it can handle up to 30 ARMS of current under steady state conditions.

The EPC9194 is compatible with a wide range of controllers from different manufacturers, enabling rapid development and reduced design cycles. The EPC provides a control interface board (EPC9147X) to operate this inverter reference design using a common BLDC motor. The EPC9194KIT includes the EPC9194 evaluation board and controller board, making it easy to connect the board to the microcontroller design suite:

• EPC9147A controller board, used to connect to Microchip's popular microcontrollers

• EPC9147C controller circuit board for connecting to ST's popular microcontrollers

• EPC9147B controller circuit board for connecting to TI's popular microcontrollers

• EPC9147E controller circuit board for connection to a variety of general purpose microcontrollers

Alex Lidow, CEO of EPC, said: "Designers can use our GaN FETs to create lighter, more efficient, battery-powered motor drivers for e-mobility and robotics applications. Gallium nitride devices enable motor systems to be smaller, lighter, quieter, more powerful, and more accurate while improving EMI, reducing the use of EMI filters and capacitors, and eliminating the need for electrolytic capacitors and input filter inductors."