Led driver for CE approval

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 We have developed 6W Led driver using LNK606DG with input range 85-300VAC and with output of 10.5V/0.55mA. For this product we plan to take CE approval since this led lamp is used in industrial application. But the driver will failed in Radiated emission test having more Average and Quasi peak values than the limits, and also in Harmonics & Flicker test IEC 61000-3-2. 

Please suggest us to overcome all the drawbacks to get approved in compliance test. 





Typical power supply will need to pass Radiated Immunity test. So you really need to address this problem.

You can basically addressed radiated immunity by

1. Layout - reducing area of switching loops

2. Damp the diode current waveforms or used diodes with low trr. Output diode and primary clamp diode current waveforms should have minimum ringing to addresses radiated problem.

You can refer to the appnote (snubber section and minimizing loop area on this appnote)


Good transformer design/construction is a big factor to minimize these parasitics that causes undamped oscillations resulting to poor emi performance. Pls refer to the appnote for some design tips in designing transformer



Ok. In our circuit output diode damp circuit is not included we will use the damp circuit across the output diode but across primary clamp circuit we used damp circuit...  


We appreciate your suggestions and help.