EPC GaN FETs Enable Premium Performance at Low Cost for E-bikes, Drones, Robotics

Article By : Efficient Power Conversion Corp.

EPC's EPC9167 GaN-based inverter reference design enhances motor system performance, range, precision, torque, all while lowering overall system cost.

Efficient Power Conversion Corp.’s (EPC) EPC9167 is a 3-phase BLDC motor drive inverter that uses the EPC2065 eGaN FET. The EPC9167 operates from an input supply voltage between 14 V and 60 V (nominal 48 V) and has two configurations – a standard unit and a high current version.

The EPC9167 standard reference design board is a 3-phase BLDC motor drive inverter board featuring the EPC2065 eGaN FET rated at 3.6mΩ maximum RDS(on), 80V maximum device voltage. This standard configuration uses single FETs for each switch position and can deliver up to 20 ARMS maximum output current.

A high current configuration, the EPC9167HC, version of the reference design uses two paralleled FETs per switch position with the ability to deliver up to 42Apk (30ARMS) maximum output current.

Both versions of the EPC9167 contain all the necessary critical function circuits 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. The boards also feature the STMicroelectronics, STDRIVEG600, smart motor drive GaN half-bridge driver.

The EPC9167 boards measure just 130-by-100mm (including connector). The boards can also be configured for multiphase DC-DC conversion and support both phase and leg shunt current sensing.

Major benefits of a GaN-based motor drive are exhibited with these reference design boards, including lower distortion for lower acoustic noise, lower current ripple for reduced magnetic loss, lower torque ripple for improved precision, and lower filtering for lower cost.  The EPC9167 boards’ lower weight and size enable incorporation of the drive into the motor housing and supports low inductance, higher power density motors.

EPC provides full demonstration kits, which include interface boards that connect the inverter board to the controller board development tool for fast prototyping that reduce design cycle times.

The default setting for the GaN-based motor drive kit is 100kHz switching frequency and 14ns deadtime. While the kit is designed to be programmed for different frequencies and deadtimes, operation at high frequency around 100kHz allows for the elimination of electrolytic capacitors and the use of lower capacitance, and reduce the motor losses. Operating the boards with very small low deadtime of around 14 ns allows higher torque per ampere. The joint effect is to improve inverter and motor system efficiency of more than 7% vs. a silicon MOSFET solution which typically operates at 20kHz and 500ns deadtime.

“GaN-based inverters increase motor efficiency while reducing their cost and delivering the same performance as an expensive motor using a silicon MOSFET-based inverter,” said Alex Lidow, CEO of EPC. “This enables motor systems that are smaller, lighter, less noisy, have more torque, more range, and greater precision.”

 

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