What does input capacitor mean

What is input capacitance?

The input capacitance is the capacitance a signal source sees, when you connect the source to that IC pin. This means, if you apply a logic HIGH to that input pin your source has to supply sufficient charge to charge up the capacitance to the desired voltage level.

How to compensate input capacitance?

Input capacitance is easily compensated by adding a feedback capacitor into the circuit. The value of the feedback capacitor should be just large enough to achieve the desired overshoot response, because larger values cause a loss of high-frequency performance. 1. Ron Mancini, Op Amps For Everyone (Newnes Publishers, 2003).

What is the capacitance of a capacitor?

Due to the large size of the farad, capacitors typically have capacitance in microfarads (µF, 10 −6 F), nanofarads (nF, 10 −9 F), and picofarads (pF, 10 −12 F). A dielectric material is the insulating substance between the plates of a capacitor.

What is differential input capacitance?

The differential input capacitance parameter, Cid, is the same as the common mode input capacitance, Cic. It is the input capacitance a common mode source would see to ground. It is expressed in units of farads. Morgan Jones, in Building Valve Amplifiers (Second Edition), 2014

Why is input capacitance hard to avoid?

Input capacitance is hard to avoid because the op amp leads have stray capaci-tance and the printed circuit board contributes some stray capacitance, so many internally compensated op amp circuits require external compensation to restore stability.

How does a capacitor work?

The capacitor charges and discharges cyclically. This results in an AC current flowing through the capacitor, with the capacitor acting as a reactive component that impedes the flow of AC to a degree that depends on the frequency of the AC signal. The concept of the capacitor dates back to the 18th century.