1.25-kW Small-Form-Factor GaN Inverter Reference Design



This reference design from Texas Instruments (TI) is a three-phase inverter with a continuous power rating of 1.25 kW at 50°C ambient and 550 W at 85°C ambient for driving 200-V AC servo motors. It features 600-V LMG3411R150 Gallium Nitride (GaN) power modules with an integrated FET and gate driver mounted on an 1.95-mm Insulated Metal Substrate (IMS) board for efficient heat dissipation. Isolation and control circuits are mounted on separate FR-4 boards - the dimensions of the design are 80 mm × 46 mm × 37 mm, including heatsink, control, isolation, and power stage. This ultra-small form factor, coupled with the ability to be natural convection fanless cooled, allows for easy integration of the drive with the motor, reducing the required cabinet space by up to 50% and cable lengths by up to 90 m in 6-axis motor applications including robotics, CNC machines, and so forth.

  • 600 V, 6-A LMG3411R150 GaN enables a power density of 150 W/in3 in 50°C ambient conditions up to 1.25 kW and in 85°C ambient conditions up to 550 W
  • Ultra-small form factor and natural convection fanless cooling allows easy integration of the drive with the motor-saving floor space and cabling costs
  • Very fast switching transition (<5 ns) with minimal switch node voltage ringing reduces EMI
  • High-efficiency power stage (peak efficiency >99% at 32-kHz PWM) reduces heat-sink size
  • Protection against gate undervoltage, device overcurrent, and overtemperature

For more information, visit www.ti.com.