Analyzing losses using junction temperature of 300V 2.4kW 96% efficient, 1MHz GaN synchronous boost converter

New techniques for measuring and analyzing losses in GaN power converters are presented. A 2.4kW synchronous boost converter, switching 300V at 1MHz with normally-off, AlN-base gate, AlGaN/GaN HFETs [1], serves as a vehicle to substantiate the results. An infrared camera is utilized to accurately measure temperatures of the upper and lower switches, as a function of switched current. These temperature measurements are correlated to loss in the respective switches, utilizing temperature data obtained via DC loss measurements. The higher temperature observed in the lower switch results from the switching loss in that switch, and is clearly evident in the thermal images. Analysis of the temperature dependence exposes the loss due to dynamic on-resistance and the switching loss. The extracted parameters accurately model both the efficiency and junction temperatures versus switching current.

[1]  K. Boutros,et al.  Normally-Off GaN-on-Si transistors enabling nanosecond power switching at one kilowatt , 2013, 71st Device Research Conference.

[2]  Y.-F. Wu,et al.  Total GaN solution to electrical power conversion , 2011, 69th Device Research Conference.

[3]  Karim S. Boutros,et al.  A 95% Efficient Normally-Off GaN-on-Si HEMT Hybrid-IC Boost-Converter with 425-W Output Power at 1 MHz , 2011, 2011 IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS).

[4]  Brian Hughes,et al.  Recent advances in GaN power electronics , 2013, Proceedings of the IEEE 2013 Custom Integrated Circuits Conference.

[5]  Y.-F Wu.  Paralleling high-speed GaN power HEMTs for quadrupled power output , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[6]  S. Heikman,et al.  A 97.8% Efficient GaN HEMT Boost Converter With 300-W Output Power at 1 MHz , 2008, IEEE Electron Device Letters.

[7]  Michael A. Briere.  The Power Electronics Market and the Status of GaN Based Power Devices , 2011, 2011 IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS).

[8]  K. Boutros,et al.  1200-V Normally Off GaN-on-Si Field-Effect Transistors With Low Dynamic on -Resistance , 2011, IEEE Electron Device Letters.