LM5146-Q1: MOSFETs selection

Alex Teryohin

Part Number: LM5146-Q1
Other Parts Discussed in Thread: LM5146

Hi, all.

I've noticed there are different MOSFETs for high-side and low-side.

Can somebody explain the reason for selecting different MOSFETs?

Is it mandatory? Can I use the same MOSFET type for high and low sides?

Best regards,

Alex

0 Andy Chen over 2 years ago

Hi Alex,

It depends on the duty cycle and switching freq.

If duty cycle below 30%, HS FET switching loss maybe larger than conduction loss, then need to select FET with smaller Cds and Cgd.

you can use LM5146 Calculator or Webench to check the power loss and then select proper FET for HS and LS

B R
Andy

0 Alex Teryohin over 2 years ago in reply to Andy Chen

OK. I understand. Thanks a lot!

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