Quick question on component placement

Steve Joblin

when do you stop being a Newbie? (retorical question)

Is there any difference between (A) and (B) (real question)... placing a capacitor after the capacitor between the "junction" of the two lines or placing a capacitor before the "junction" of the two lines?


(A)

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(B)

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David B

Yes, they are different.

Heres an easy way to see it. Imagine the series cap is very small and the parallel cap is large.

With the upper configuration, the left side will experience the low impedance of a large capacitor.

But by the lower configuration, the left end will experience the high impedance of the small cap.

It may or may not matter, depending on the circuit.

David

Steve Joblin

Interesting... I think I am actually learning!!! what if the caps are the same value (both small , like .1uF)?

David B

I would think that if the capacitors were about the same then the two configurations would behave practically the same.

If you want to get down to exactly how they would differ then I think you'd need to start taking into account what kind of circuitry is attached to each end.