LTC3872 boost converter 5V-40V

Hello,

I have modelled the LTC3872 as a boost converter in the configuration of Capture01.PNG.

It oscillates as in the Capture02.PNG.

Do you have any suggestion why and how to fix it?

As a test, I have replaced the MOSFET with a different part (Si7850DP, see Capture03.PNG) and now it works.

It provide 40V output [V(200)] and the FB voltage [Vref] is 1.2V after the transient (see Capture04.PNG).

Does this give us any clue?

Thanks

Best Regards

Max