I have a few questions regarding ESR of capacitor:
1. How to calculate ESR from datasheet?
2. for most low ESR capacitor, there are in SMT package. The problem is, I need to do breadboard prototyping, which SMT will be very inconveniece. how to get around with that?
You can't "calculate" ESR from a data sheet; the value will be (or not) given to you in a data sheet. Example: https://www.niccomp.com/Catalog/nspv.pdf
As far as using SMTs in prototypes is concerned, you can always use very, very short wires and mount them on your board, and then using a drop of some flexible glue secure them on the board.
Regards,
IanP
You can't do it witout soldering. Glue is just to physically attach this component to the board, and it can be upside-down, so you have access to solder/join very short wires..
Regards,
IanP
If the dissipation factor (DF) is given, you can calculate the ESR from
.
ESR = (DF) (Xc)
.
Where
. Xc = capacitive reactance = 1/(2Pi X f X C).
.
Remember that this calculation is only valid for the frequency at which the DF is specified.