Hi everyone. According to STM32F405RG datasheet page 82, the value of VCAP capacitors must be 2.2uF . My question is, can 10uf capacitor also be used for VCAP pins safely? is it will be reliable for long term device working? Thanks for your time.

[TDK]

Not sure you're going to get a definitive answer here. Presumably ST uses 2.2 uF here and does their testing with it, thus that is what they recommend and guarantee. Will it work with other values like 10uF? Probably. Will it always work? Maybe. ESR is probably more important than capacitance.

Caps have a considerable high tolerance and variable with package size, dielectric, and temperature effects. Just because 10uF works at ambient doesn't mean it'll work at all temperatures. Maybe that matters in your application, maybe not.

I have used 4.7uF caps for VCAP to cut down on BOM count without issues.

[SJafa.2]

Hi TDK and thanks for your reply.

My purpose to use 10uF caps is also for reducing BOM count. but now i doubt to do this. hope to someone can clarify this.