SMPS with TOP249YN
we uses the SMPS with TOP249YN.The specs are 18-22V/2.5A single output. But sometimes the ouput short circuit causes the TOP249YN malfunction(blows).Do you have any idea or suggestions? Regards, Ilker.
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Without short circuit, the SMPS is good,the output voltage and current are usual. But when the output short circuited and the input voltage applied to SMPS,the TOP249YN blows.And also in some cases, after startup the output short circuit gives the same failure.
Regards,11
I read some PI forums and I think that the root cause may be TOP249YN batch problems. Because we produce this SMPS for a long time without any component change. Is it possible? Our batch number are 0Q979A and 0V990A.
Regards. Ilker.
We never had any issue regarding batch problems when shorting the output. I assume you are placing the short at KN2 connector. Am I right?
The first thing I would like to check is the flux density and the current in the primary winding of the transformer when the short is applied.
Can you please post your transformer design and VDRAIN and IDRAIN waveforms when the short is applied and the supply fails?
Could you let me know how the short circuit test was performed?
And PLS upload drain pin voltage and current thorugh drain pin of the restart during the short circuit test.
Regards