ir 2110 is fine. cause mosfet burns instantly and i unplug the circuit. after changing the mosfets, i test the circuit with low voltage and it works fine.No - they'll be fine as the total rail is < 600V - resistors are a very BAD idea in this application - can you see why danadakk ?
also - check all your fets prior to power up to make sure they aren't short - but it is very easy to kill the IR2110 if the layout is too open and the mid point of the totem pole of fets goes negative, you need some film/foil caps right across the totem poles.
Hi Dana. thank you for your quick response.IR2110 possibly breaking down (not meeting its max specs) ? But still operational at
lower V.....
Scope capture qualified to trigger when both mosfets are on to possibly capture
event, while also capturing gate drive and source/drain conditions.
MOSFETs have gate to source/drain short ? Or just source/drain lead open or shorted,
another clue.
Regards, Dana.
sorry i forgot to update the schematic. i used 4 uf4007 in parallel with mosfets and yet result was as mentioned before.Sure sounds like body diode in MOSFETs not fast enough and you are exceeding Vgsmax
and rupturing gate oxide inside MOSFET. Its ~ worst case 1 uS for internal diode.
Maybe try some ultrafast diodes in parallel with the internal body diode, something on
the order of 100 nS Trr.
You might replace load in bridge with just a R rated for approximate current levels and using
a scope verify no layout problems causing unexpected transients. Use scope triggering to capture
out of spec transients on Vgs. Then try some ultrafast diodes and L load.....
There are people here much more experienced in inverters than me, so take my advice with a
gain of salt.....
Regards, Dana.
HiHi,
I guess UF4007 is in the range of MOSFET body diode voltage drop. If so, then the body diode still becomes conductive. This should be avoided with the external diode.
Body diodes are not especially designed in, they automatically happen when MOSFETs are produced.
Klaus
Yes on turnoff question.sorry i forgot to update the schematic. i used 4 uf4007 in parallel with mosfets and yet result was as mentioned before.
to my knowledge body diodes are for reverse current after turning off the circuit, yes?
but i never got to that part and mosfets burns instantly when their supply plugs in!!
Both diodes should be fast at turn ON. This is not the problem.But it is fast for sure at 75 nS at 1A.
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