Boost Converter Snubber - PCB layout

Michael Dalton

Hello,

I have made a prototype boost converter (on strip board) using the MSP430 as the controller, i have a RC snubber over the switch (following the SLVA255 - Minimizing Ringing at the Switch Node of a Boost Converter guide) but was wondering how i should layout the snubber in the PCB design. The following picture shows a suggested layout for a boost converter. I'm using Altium designer for the PCB design.

I'm pretty sure that the values of R and C will need change so i was thinking of just leaving some 1206 footprints open on the board and adjust the values when i populate and test the PCB.

Should i put the R and C footprints on the underside of the board or just as close to the drain and source terminals of the NMOS as i can get??

Thanks

Michael Dalton

over 13 years ago

0 Jeff F over 13 years ago

TI__Guru**** 154526 points

the snubber will be most effective if it is placed between the drain and source of the NMOS on the same side of the board. You should be able to use a 603 capacitor and 805 or smaller resistor.

0 Michael Dalton over 13 years ago in reply to Jeff F

Intellectual 650 points

Jeff F said:

You should be able to use a 603 capacitor and 805 or smaller resistor.

Thanks

So the smaller the footprint the better?

I was just trying to make it easier on myself with the 1206 footprint, for hand soldering. :) (i have successfully hand soldered a 402 inductor in a previous project, it was sheer luck though).

Regards

Michael Dalton

0 Jeff F over 13 years ago in reply to Michael Dalton

TI__Guru**** 154526 points

Yes, the tighter the layout the better. Smaller components yield a tighter layout.

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Boost Converter Snubber - PCB layout