FET and eval board simplify GaN FET circuit design

The GS66508T enhancement mode transistor and the associated EVBHB half-bridge evaluation board from GaN System is now being shipped by Mouser Electronics. The GS66508T is a 650V enhancement mode gallium nitride (GaN) power switch with top-cooled configuration. The fully functional GS66508T-EVBHB board is easily configured into any half bridge-based topology, including synchronous boost or buck conversion, as well as pulsed switching to evaluate transistor waveforms.

The kit contains full documentation, including bill-of-materials, component part numbers, board layout and thermal management, and gate drive circuit reference design to help system engineers incorporate the GS66508T transistor into power and motor drive designs.

The GS66508T enhancement mode transistors are 55mΩ, top-side cooled FETs that feature near-chip-scale, thermally-efficient GaNPX packaging. The high-power transistors achieve extremely efficient power conversion (98.7 percent at 1.5kW) with fast switching speeds of greater than 100V/nS and ultra-low thermal losses.

GaN Systems’ Island Technology die design, combined with the extremely low inductance and thermal efficiency of GaNPX packaging, provides the GaN FETs with 45 times improvement in switching and conduction performance over traditional silicon MOSFETs and IGBTs.

The GS66508T-EVBHB half-bridge evaluation board is designed to provide electrical engineers with a complete working power stage. It consists of two 650V, 30A GS66508T GaN FETs, half bridge gate drivers, a gate drive power supply, and heat sink.

The eval board provides footprints for output power inductors and capacitors to allow designers to configure the board into pulse test mode, buck/standard half bridge mode, and boost mode. The board includes both thermocouple pads and thermal camera imaging ports to provide access to the transistor junction temperature.

The board’s operating power input is 9VDC to 12VDC, with an absolute maximum of 15V, and onboard voltage regulators create +5V for the logic circuit and +6.5V for the gate driver.