In a switching power source the compensation circuit can be simplified and operations can be stabilized without increasing.
Ceramic esr value.
Another theoretical way to calculate esr of the capacitor is to measure the ripple voltage and ripple current of the capacitor and then the ratio of both will give the value of esr in the capacitor.
Some capacitors are designed specifically for low esr but manufacturers of aluminium electrolytic capacitors do not specify esr consistently.
These products allow for the selection of esr values that are suitable for each application.
The value at 25 c and 100khz is commonly quoted with a formula provided to calculate the value at the operating frequency.
Esr of non electrolytic capacitors tends to be fairly stable over time.
Not only esr values but also the impedance frequency characteristics and other characteristic data can be.
For most purposes real non electrolytic capacitors can be treated as ideal components.
We have released a web application simsurfing where characteristic charts can be displayed and characteristic data of multilayer ceramic capacitors can be downloaded.
Typically quoted values of esr for ceramic capacitors are between 0 01 and 0 1 ohms.
However a more common esr measurement model is to apply alternating current source across the capacitor with an additional resistance.
The esr of a ceramic capacitor is so low it is fairly common to disregard it altogether for practical purposes in dc regulators.