Bode Plot and Power Supply Stability Criteria

[PovilasKubilius]

Hi,
I designed flyback SMPS and now have to design compensation around it.
I know about Bode plot and how to do it. But it seems that what ever I do and what ever path I chose I can't measure or alive the GM or PM.
I tried to go academic route and calculate everything by hand/excel but it not reflect true world measurements.
I tried to measure Plant of SMPS but noise is to strong. So can any one help me to learn how to design compensation of SMPS and how to measure it.
One of my measurements is showed in photo, DCM mode .
Thanks for help!!!!

[milos.stankovic]

Hi Povilas,

Try datasheet in attachment, chapter 7.3.11.

Regards,
Miloš

[Lakshmi]

Hi,
I designed flyback SMPS and now have to design compensation around it.
I know about the Bode plot and how to do it. But it seems that whatever I do and whatever path I chose I can't measure or live the GM or PM.
I tried to go the academic route and calculate everything by hand/excel but it does not reflect true world measurements.
I tried to measure the Plant of SMPS but the noise is too strong. So can anyone help me to learn how to design compensation of SMPS and how to measure it?
One of my measurements is shown in the photo, DCM mode.
Thanks for the help!!!!

Hope this could be helpful

https://www.youtube.com/watch?v=uMH2hGvqhlE&t=1s

[PovilasKubilius]

Can Steve.Picotest Help me on this? I know how to measure it, I don't know what part cause is positive phase.

[qdrives]

Perhaps this https://www.youtube.com/watch?v=EARVilCGl6g will help. (part 1a of multiple)

[robertferanec]

qdrives Interesting link. I watched also the EMC videos and I contacted Ali if he would be interested to have a recorded call for possible youtube video. Thanks for pointing out his channel.