Jester
Full Member level 6
When selecting devices such as capacitors, diodes, FET's etc. I was taught to select a device with 2x the voltage rating to ensure reliability.
In some cases a part with say a x1.8 rating is significantly less expensive than the next step up. For example 4.7uF input capacitor for a buck regulator with a nominal input voltage of 28Vdc
This 50V part is priced $0.28, $0.06 qty1, 1000 https://www.digikey.com/product-search/en?keywords=587-2994-1-ND
While the 80V part is priced $1.03, $0.41 qty1, 1000 https://www.digikey.com/product-detail/en/GRM32ER71K475KE14L/490-9972-1-ND/5026477
I'm inclined to use the 50V part. The buck regulator is rated 40V max, so it seems over-kill to use the 80V part. Does anyone disagree?
In some cases a part with say a x1.8 rating is significantly less expensive than the next step up. For example 4.7uF input capacitor for a buck regulator with a nominal input voltage of 28Vdc
This 50V part is priced $0.28, $0.06 qty1, 1000 https://www.digikey.com/product-search/en?keywords=587-2994-1-ND
While the 80V part is priced $1.03, $0.41 qty1, 1000 https://www.digikey.com/product-detail/en/GRM32ER71K475KE14L/490-9972-1-ND/5026477
I'm inclined to use the 50V part. The buck regulator is rated 40V max, so it seems over-kill to use the 80V part. Does anyone disagree?