GS66504B-EVBDB 650V
GaN E-HEMT Evaluation Board
User’s Guide
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GS66504B-EVBDB UG rev. 161120
© 2016 GaN Systems Inc.
www.gansystems.com 19
Please refer to the Evaluation Board/Kit Important Notice on page 29
Figure 20 Turn-off switching loss measurement (Eoff=5.5uJ, 400V/15A)
The switching loss measurements with drain current from 0 to 15A can be found in Figure 21. The turn-
on loss dominates the overall hard switching loss. Eon at 0A is the Qoss loss caused by charging Coss at
high side switch.
The turn-off loss remain almost constant from 0A up to 10A about 3.6uJ. the measured Eoff matches well
with the Eoss @400V, which indicates that turn-off energy is dominated by Eoss, the energy required to
charge Coss from 0V to bus voltage. This energy is not part of loss at turn-off, but actually part of turn-on
loss at next hard switching turn-on period. This means that with the fast turn-off speed the GaN E-HEMT
can achieve near zero turn-off switching loss.
