Evaluation of thermal performance of all-GaN power module in parallel operation

Po Chien Chou, Stone Cheng*, Szu Hao Chen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


This work presents an extensive thermal characterization of a single discrete GaN high-electron-mobility transistor (HEMT) device when operated in parallel at temperatures of 25 °C-175 °C. The maximum drain current (ID max), on-resistance (RON), pinch-off voltage (V P) and peak transconductance (gm) at various chamber temperatures are measured and correlations among these parameters studied. Understanding the dependence of key transistor parameters on temperature is crucial to inhibiting the generation of hot spots and the equalization of currents in the parallel operation of HEMTs. A detailed analysis of the current imbalance between two parallel HEMT cells and its consequential effect on the junction temperature are also presented. The results from variations in the characteristics of the parallel-connected devices further verify that the thermal stability and switching behavior of these cells are balanced. Two parallel HEMT cells are operated at a safe working distance from thermal runaway to prevent destruction of the hottest cell.

Original languageEnglish
Pages (from-to)593-599
Number of pages7
JournalApplied Thermal Engineering
Issue number1
StatePublished - 5 Sep 2014


  • GaN HEMTs
  • Parallel operation
  • Power module
  • Power semiconductor devices
  • Static parameters

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