Metalized- polyester vs. Metalized-Acrylic capacitors

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Jester

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I'm working on a RMS conversion circuit using a LTC1966 https://www.linear.com/product/LTC1966

The output stage of this device requires a capacitor for the averaging function, and the data sheet calls for a film capacitor such as a metalized polyester. After doing a quick search most if not all the metalized polyester capacitors are fairly large and through-hole. I prefer to use an SMT capacitor.

I found these (Metalized-Acrylic), in a 1210 SMT package : https://www.digikey.ca/product-detail/en/FCA1210C105M-G2/338-2778-1-ND/2614427

Is this a suitable substitute for the larger through hole Metalized-polyester style capacitor?


One other comment/question, in the past we experienced degradation of film capacitors due to the oven temperatures during the reflow process, we actually had to start using a ceramic capacitor even though the characteristics were far from ideal because the fab. house seemed incapable of regulating the time and temperature. The data sheet states the Metalized-Acrylic capacitor can withstand 235°C for 200 seconds, any thoughts on this aspect?
 

The main concern appears to be leakage of the capacitor, so any capacitor that has low leakage should be fine. They state that the capacitor resistance should be 1000 times the output impedance (which is 95kΩ maximum) for 0.1% degradation, which would be 95MΩ for the minimum capacitor resistance.
 

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