I have designed in ADuM4135 for a half bridge pulse generator. I have problem with the IC breaks down. At this writing I have blow up probably about 50 IC during prototype testing. The IGBT:s survives almost every time
- I have tried both with and without Desat and Miller clamp.
- I have decoupling capacitors very, very close to pin, even tried to solder direct on pins
- I have back diode at Desat input to not get problem with negative spikes
- Have about 20kV/µS, should be well below spec
I'm using a bit higher supply Voltage than stated in app notes, I have +20V/ -6V What I can see this is also
well below spec?
It seems like the output stage goes to short circuit. Sometime I also have noted a latch up, the driver stop working
and draws much current, but after power cycling it works again.
What can be the reason? Any ideas?