TPS23755EVM-894: C7 and C31

Hirotsugu Kobayashi

Mastermind 9530 points

Part Number: TPS23755EVM-894

Hi, team.

What is the role of EVM C7 and C31?
Are they necessary parts?

over 5 years ago

0 Michael Pahl over 5 years ago

TI__Mastermind 21320 points

Hello Hirotsugu,

This capacitor suppresses EMI by providing a return path for noise that is coupled across the flyback transformer.

I have never seen a design without them.

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Hirotsugu Kobayashi over 5 years ago in reply to Michael Pahl

Mastermind 9530 points

Hi, Michel

I understand that it is placed between PGND and GND like C24 and C32 for noise purposes, but I have never seen a capacitors between VIN and GND like C7 and C31.

0 Michael Pahl over 5 years ago in reply to Hirotsugu Kobayashi

TI__Mastermind 21320 points

Hello,

It is a low pass filter that helps with EMI. What is your question?