DPA424PN problem: IC burns or explodes
Hello there!
I have been facing the following problem: sometimes at the moment I turn on the power supply (designed using PI Expert 7, schematics attached) the DPA424PN burns (with burn marks on pin 6, Drain) or even explodes (!). And to make things a little more difficult, that is a "sometimes-problem" that does not necessarily happen on the first turning on (I tried to run a test turning on and off 8 mounted circuits repeatedly during several hours and no IC burned)...
Has anybody ever faced a similar problem before? Any hint to help fixing the problem will be very welcome.
Thanks in advance.
Comments
Ok, here it goes.
It seems you were right. During DPA start up, drain voltage goes above 300 V. What are the possible causes for such behavior? Transformer maybe?
Thanks again.
- Excessive primary leakage inductance
- Poor primary snubbering
- Excessive primary leakage inductance
- Poor primary snubbering
Ok, I will check the first option first. For the snubber circuit I used comercial values components calculated by PI Expert but the transformer was built "as close as possible" to the parameters suggested.
Thank you very much.
Pls. capture the Drain voltage and current with at least 10 Ms/s scope and 50 MHz bandwidth, at the moment of power up at maximum input voltage. Post the waveforms.
The most common cause of failure is exceeding Abs Max Drain voltage.