Application-Oriented Threshold Voltage Shift of GaN-HEMTs – Test Bench and Results

Kohlhepp B, Breidenstein D, Stöcklein N, Dürbaum T, Dieckerhoff S (2025)

Publication Type: Journal article

Publication year: 2025

Journal

DOI: 10.1109/JESTPE.2025.3607031

Abstract

Due to the low on-state resistance and fast switching transitions, GaN-HEMTs are promising for building highly efficient power converters. However, charge trapping effects within the semiconductor structure worsen various parameters of the transistor. Besides the deteriorated on-state resistance, also threshold voltage shifts occur. These impact the switching behavior as well as losses and can cause Miller induced turn-on. As data sheets do not give information regarding this effect, the power converter designer needs to conduct own measurements. Several parameters like temperature, drain and gate bias, as well as switching conditions impact charge trapping. Additionally, charge trapping effects show time constants ranging from µs to hours. These circumstances call for a specific test bench to assess the threshold voltage under conditions close to the intended application. By using standard laboratory equipment typically present in every power electronics lab, this paper presents a cost-effective solution to obtain the threshold voltage under application conditions. The device operates under hard- or soft-switching, and the converter operation is interrupted by short measurement intervals to acquire the threshold voltage. With a nominal value of 1.1 V, the results show a shift of ≈1 V in hard-switching and ≈0.9 V in soft-switching operation of up to 10000 s.

Authors with CRIS profile

Involved external institutions

Technische Universität Berlin Germany (DE)

How to cite

APA:

Kohlhepp, B., Breidenstein, D., Stöcklein, N., Dürbaum, T., & Dieckerhoff, S. (2025). Application-Oriented Threshold Voltage Shift of GaN-HEMTs – Test Bench and Results. IEEE Journal of Emerging and Selected Topics in Power Electronics. https://doi.org/10.1109/JESTPE.2025.3607031

MLA:

Kohlhepp, Benedikt, et al. "Application-Oriented Threshold Voltage Shift of GaN-HEMTs – Test Bench and Results." IEEE Journal of Emerging and Selected Topics in Power Electronics (2025).

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