Hello wf kan,

May I ask if you're using a ripple probe in this measurement? If not, we suggest that you use a ripple probe for probing output voltage. This will filter out the noise that you are seeing in the oscilloscope.

Kindly see page 32 of DER-736 (DER-736 7W 12V500mA 5V200mA 85-440VAC Non-Iso Flyback LNK3696P (power.com)) for reference on creating output ripple probe.

We hope that this will resolve your inquiry.

Thank you and have a great day ahead.

Hi Tommy, 

Thanks for advise. 

Currently the accessories, BNC Adapter is not available, so I can't make the ripple probe to check the waveform.

Btw, is there any other way to reduce the ripple & noise, although LC Pi Filter circuit is apply ? 

Pls advise.  Thanks. 

Hello wf kan,

I hope you're doing fine.

I'm sorry to hear that the accessories is not available at your end but without the correct measurement setup, the oscilloscope will still capture the noise that is picked up by the oscilloscope probe. Hence, when obtaining output waveforms (output voltage/output ripple), the best practice is to use a ripple probe.

Thank you and stay safe.