Extraction of Dynamic On-Resistance in GaN Transistors: Under Soft- and Hard-Switching Conditions

In this paper we present a new measurement technique for extracting dynamic on-resistance (R
_dson
) of GaN transistors. Dynamic R
_dson
of commercial GaN transistors in soft-switching and hard-switching conditions have been measured. By comparing the dynamic R
_dson
in both switching schemes, it is found that the off-state drain voltage stress is the main cause for the increase of dynamic R
_dson
, while the switching losses in the hard-switching transient could cause additional trapping and degradation, possibly due to channel hot electrons/phonons.