Programmable Devices
CPLDs, FPGAs, SoC FPGAs, Configuration, and Transceivers

EN2392QI Problem

Altera_Forum
Honored Contributor II
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We designed a board that has a lot of the EN2392QI devices. We copied the circuit from an existing board that uses them but we adjusted the components needed for each voltage level. Now the boards will power up once or twice but then we start losing the EN2392QI part. They fail shorted on the 12V input. What we have discovered so far is that we have too much capacitance on a few of them. I added up everything on the board, even caps that are not close by physically. Also we do not have the snubber circuit from the SW pin to the M/S pin. Before you say that these are the problem I need to point out that we have a blown EN2392QI that has less than 25% of the recommended max capacitance value. In theory this one should not have blown out if too much capacitance without the subber is the problem. I did read on here that someone had a problem with them dying if the output did not discharge fully before power was reapplied. That could be a problem as we do have a lot of caps and not a lot of load as we have not finished programming the board. Let me know what you think. Thanks.

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