I understand the absolute maximal voltage on the switch node to be 80V. However, I am seeing ringing on my switch node during the turn on time of either top or bottom FET, which I'd like to understand how bad of a problem it is. I understand no amount of ringing is good, so will certainly look into why there is ringing in the first place (I followed all of the layout guide-lines to the T). In my application, Vin can vary anywhere from 5V to 60V. When Vin is ~52V, the ringing is as high as 66V for less than 2ns so I stopped raising the voltage to avoid permanently damaging the FETs. See the attached image for an example of my switch node waveform.
Is the 80V maximum voltage a hard limit? Meaning if it is 80V for any finite amount of time irreversible damage will occur? Or is ~2ns of 80V probably going to be OK?
I understand there is no body diode in GaN FETs, is that true with this package? I understand due to the construction of the FET, there is "body diode like" properties, and do believe I see this taking over in some circumstances in my waveform, but that doesn't clamp until the voltage is a couple voltage above Vin or below Ground for more than ~10ns. So assuming this body diode like property is somewhat slow, relatively speaking. Meaning the 2ns spikes I'm seeing happen too fast to get caught. To that end, I'm wondering if really fast and low capacitance schottky diodes would help clamp these spikes I'm seeing. Thoughts?
Thanks in advance,
Ryan