Pi filter location

Posted by: jgb56 on 06/19/2012

Hi,

We have suscessifly designed several buck boost SMPS using your LNK3XX series.
I do have a question about the pie filter. Is it possible to move the filter in
front on the half wave diodes (Din1 & Din2)to help with conducted emisions. Also
can Rf stay in front of the filter or does it matter

Comments

Thanks a lot for using PI part! Could you tell me which schematic/document are you talking?
With a schematic, we can share the same picture.

Thanks again.

Hi,

If you look at page 1 figure 1 1b on AN37 thats the basic circuit. I would like to know if i can move Rf Din1 and Din2 to the right of Cin1 Lin1 Cin2 filter.we are using a LNK306.

I donot think you can move them. If the input cap are moved to AC side, the ripple of the buck boost input will be very high, since the cap will follow the AC input.

Hi,

Can we continue the discusion off line? Do you have an direct email address.

my email is: Peter.Liu@powerint.com