EMI filter

[Rajinder1268]

Hi,
I need some help in designing a EMI filter for a buck regulator, used in automotive application, power from car battery, I have a fuse and reverse voltage protection.
I am using a TI LM53600 device. The datasheet has ESD ratings of 2kV HMB.
Is there a simple pi filter solution to eliminate high frequency noise?
Thanks in advance

 

[KlausST]

Hi,

You headline talks about EMI. Which is "sending out" HF.

Fuse, reverse protection, ESD ... has nothing to do with EMI.

EMI:
There is wired and radiated HF noise. Both need different solutions.
But besides schematic, the PCB layout has amost identical impact on EMI.
Thus we need to see both, schematic and PCB laoyut to give good assistance.

A well designed PCB maybe needs no additional filters.
For a badly designed PCB it´s huge effort and a lot of trial and error to get good EMI values.

Klaus

 

[Rajinder1268]

Hi,

You headline talks about EMI. Which is "sending out" HF.

Fuse, reverse protection, ESD ... has nothing to do with EMI.

EMI:
There is wired and radiated HF noise. Both need different solutions.
But besides schematic, the PCB layout has amost identical impact on EMI.
Thus we need to see both, schematic and PCB laoyut to give good assistance.

A well designed PCB maybe needs no additional filters.
For a badly designed PCB it´s huge effort and a lot of trial and error to get good EMI values.

Klaus

Hi
I have done a schematic but not PCB layout. I wanted to find a pi filter solution or similar to add to the schematic so it covers the EMI issues. I have seen one fit components that do both EMI and transients. Would those be ok to use?

--- Updated Jun 29, 2022 ---

Hi,

You headline talks about EMI. Which is "sending out" HF.

Fuse, reverse protection, ESD ... has nothing to do with EMI.

EMI:
There is wired and radiated HF noise. Both need different solutions.
But besides schematic, the PCB layout has amost identical impact on EMI.
Thus we need to see both, schematic and PCB laoyut to give good assistance.

A well designed PCB maybe needs no additional filters.
For a badly designed PCB it´s huge effort and a lot of trial and error to get good EMI values.

Klaus

Hi,
Thanks. Are there good design guidelines to avoid the EMI filter and rely on good PCB layout?