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Power Management ICs Forum Discussions

nikhil
Level 1
Level 1
First reply posted First question asked Welcome!

I am using ICE3AR2280 for flyback converter. I have designed and calculated all required component value. Everything is fine but I am getting osccillation between CS pin and ground. I am attaching 3 DSO picture for the reference. 1st figure showing flyback primary winding voltage, 2nd figure showing voltage across Drain pin and CS pin and 3rd showing voltage across CS pin and ground.

What will be the main reason for oscillation between CS pin and ground?

Please help me out.

Link of all photos:

https://drive.google.com/drive/folders/1KWXkiok9OagWm5kkxNWWGutpdvsu5Ycu?usp=share_link

Thanks in advance.

 

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1 Solution
GA
Moderator
Moderator
Moderator
25 solutions authored 100 sign-ins 50 replies posted

Hi @nikhil ,

Thank you for posting in the Infineon community.

Oscillations are seen when the switch is turned off, Various factors can influence it,

  1. External noise coupling during measurement. This effect can be reduced by using a ground ring in the probe while measuring.
  2. Placement of CS resistor. The current loop formed with the inductance of the track may lead to oscillation. This effect can be reduced by placing the CS resistor close to the CS pin. (Reducing current loop).
  3. Output capacitance of the switch (Coss) and leakage inductance of the transformer may resonate and create oscillations.

Reach out to us for any further queries.

Best Regards,

GA

 

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3 Replies
GA
Moderator
Moderator
Moderator
25 solutions authored 100 sign-ins 50 replies posted

Hi @nikhil ,

Thank you for posting in the Infineon community.

Oscillations are seen when the switch is turned off, Various factors can influence it,

  1. External noise coupling during measurement. This effect can be reduced by using a ground ring in the probe while measuring.
  2. Placement of CS resistor. The current loop formed with the inductance of the track may lead to oscillation. This effect can be reduced by placing the CS resistor close to the CS pin. (Reducing current loop).
  3. Output capacitance of the switch (Coss) and leakage inductance of the transformer may resonate and create oscillations.

Reach out to us for any further queries.

Best Regards,

GA

 

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nikhil
Level 1
Level 1
First reply posted First question asked Welcome!

Thankyou very much. 

 

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