Evaluation board simplifies GaN power FET try-out

December 29, 2015 // By Graham Prophet
GaN Systems (Ottawa, Canada) has configured a half-bridge evaluation board to demonstrate its GaN enhancement mode power transistors in real power circuits. The fully functional GS66508T-EVBHB Evaluation Board can adopt any half-bridge-based topology, including synchronous boost and buck conversion modes, as well as pulsed switching to evaluate transistor waveforms.

Accompanied by a quick start instruction guide and YouTube video links, the development kit comes with full documentation, including bill-of-materials component part numbers, PCB layout and thermal management, and a gate drive circuit reference design to help system engineers develop their products.

Designed to provide electrical engineers with a complete working power stage, the evaluation board consists of two 650V, 30A GS66508T GaN FETs, half-bridge gate drivers, a gate drive power supply, and heatsink. The GS66508T high power transistors are based on GaN Systems’ Island Technology and belong to its 650V family of high density devices which achieve extremely efficient power conversion with fast switching speeds of >100 V/nsec and ultra-low thermal losses. GaN Systems claims to be the only company to have developed and commercialised a comprehensive portfolio of GaN power transistors with voltage ratings of 100V and 650V and current ratings from 7A to 250A. Using its die design combined with the extremely low inductance and thermal efficiency of GaNPX packaging, GaN FETs claim a 45-fold improvement in switching and conduction performance over traditional silicon MOSFETs and IGBTs. The 30A/50 mΩ GS66508T GaN power transistors are top-side cooled, and feature near chip-scale, thermally-efficient GaNPX packaging. At 1.5 kW, this device’s power conversion efficiency is rated at 98.7%, a value which can be reproduced in the owner’s lab.

The Evaluation Board provides footprints for output power inductors and capacitors so users may configure the board into desired boost or buck operational mode. Access to the transistor junction temperature is provided by both thermocouple pads and thermal camera imaging ports. Power input should be 9 VDC to 12 VDC, with an absolute maximum of 15V. On-board voltage regulators create +5V for the logic circuit and +6.5V for the gate driver. The board operates in three modes: pulse test mode, buck/standard half-bridge mode, and boost mode. A full user guide is available here.

GaN Systems; www.gansystems.com