TNY becomeing too hot

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Hi

I've designed an 18W LED deriver using TNY280. In constant voltge mode it works properly, but when the mode is changed to constant current the TNY becomes too hot and after a while it stops working. Which problem mat cuase this? the wrong clamp circuit (considering in CV mode it works correctly), or wrong feedback circuit?

The feedback circuit photo has been attached.

 

Please guide me. Thank you

Please check if the power consumed at CV mode is similar to CC mode. If you verify that the temperature at 18W is ok at CV mode, If you are drawing more power at CC mode, then it's probably the feedback. Adjust your CC circuit if necessary to give 18W.