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LNK3206D Gournd drifting

Posted by: John Zigrang on Thu, 09/09/2021

In an off-line switch, is the GND generated has a floating / drifting component to it?

I am taking the AC source before the Half Bridge and dividing down to measure the amplitude and frequency.

I find that the AC varies a lot in amplitude which causing jitter in frequency because the ac crossing point is moving up/down.

My design if for 3 phases, but I have not been able to get 1 to work.




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Schematice 2.73 MB
Scope Image at Test Point 770.56 KB


Submitted by PI-ZBDelta on Thu, 09/16/2021

Hi John Zigrang,

Are you experiencing this problem only while LNK3206 is operating?

Or do you still have this problem even if you remove the buck converter?