Analysis and modeling of OFF-state hysteretic losses in GaN power HEMTs

Dhawal Dilip Mahajan*, Sourabh Khandelwal

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


We present a detailed analysis of large-signal Sawyer–Tower measurements on a power GaN HEMT device in OFF-state. The measurements show hysteresis which results in an energy loss dissipated as heat in the range of sub-μJ's. We model this important phenomenon in this paper using a previously calibrated model of the same device. We propose two models, one with linear Effective Series Resistance (ESR) and another using non-linear ESR (NLESR). It is found that to model the non-linear profile of hysteretic curve from Sawyer–Tower measurements, non-linear ESR and output capacitance are needed. The similarities and differences between these two models have been explained in detail. While linear ESR is shown to be a simple model for modeling the hysteretic losses, non-linear ESR and output capacitance model the dynamics of charge imbalance that occurs during the charging and discharging processes more accurately. A detailed analysis based on recent literature suggests that 2DEG electron trapping by acceptor type traps in the underlying buffer layers are the primary cause of this charge imbalance.

Original languageEnglish
Article number107995
Pages (from-to)1-10
Number of pages10
JournalSolid-State Electronics
Publication statusPublished - Jun 2021


  • Sawyer–Tower measurements
  • Power GaN HEMTs
  • ASM-GaN compact model
  • Hysteretic loss
  • Effective Series Resistance (ESR)
  • Trapping


Dive into the research topics of 'Analysis and modeling of OFF-state hysteretic losses in GaN power HEMTs'. Together they form a unique fingerprint.

Cite this