Why less amount of ESR capacitance is preferred for decap?

[supra924]

Decap

Why always less amount of ESR capacitance are prefered for decap application?
where can we find correct info?

 

[ambreesh]

Re: Decap

Dear supra924,

A decoupling cap if that is what you mean by DeCap is basically to help the circuit to take care of transient loads and keep the supply in the required limits of operation.
Whenthe Decap provides the instantaneous charge that has to flow through the ESR also and that would mean a voltage drop across this ESR. So actual supply voltage avilable is Vdd-Itran*ESR and this may be below the VDD-10% requirmwnt for the circuit if ESR is large.
Hope it helps