We have existing design using TOP265 for 20W(24V/0.83A) LED driver application.
Vin = 180VAC-265VAC
Problem : Noise in all load condition. (No Load - Full Load). Please advise what is the possible problem.
If the noise is originating from the transformer, then please try to dip varnish the transformer to minimize the audible noise. Also, it is recommended to set the maximum operating flux density BM to below 3000 gauss.