Characteristics of ideal op amp
Table of Contents
characteristics of ideal op amp
Characteristics of ideal op amp
The ideal op-amp has the following characteristics
1. voltage gain of an ideal op-amp is Infinite. ideal op-amp has infinite voltage gain because for finite output voltage, the voltage difference between the inverting and non-inverting terminals (also known as the differential input voltage) is nearly zero. (Due to their nature as voltage-gain devices, op amps require a high input impedance. According to Ohm’s law, V=IR, a very high impedance is required for a voltage drop to occur across the input. Preventing the loading effect is also crucial. The current draw would be high if the impedance were low.)
2. Infinite input resistance Ri, so that almost any signal source can drive it and there is no loading of the proceeding stage.
3. Zero output resistance Ro, so that the output can drive an infinite number of other devices. (for an ideal op-amp output impedance should be Zero)
4. Zero output voltage, when input voltage is zero.
5. An ideal op-amp requires infinite bandwidth because Any frequency signals from o to ∞ HZ can be amplified without attenuation.
6. Infinite common mode rejection ratio, so that the output common mode noise voltage is zero.
7. Slew rate value for an ideal op-amp Infinite, so that output voltage changes occur simultaneously with input voltage changes. (The rate at which an op-output amp’s can change in relation to its input is known as slew rate. It is determined by how much the voltage changes over time. The time delay is 0 for a perfect op-amp. The slew rate for an ideal op-amp is therefore infinite, according to the equation.)
8. CMRR value for an ideal op-amp is infinite. The ideal CMRR is infinite. 100 dB would be the typical value for CMRR. In other words, if an op amp had desired (i.e., differential) and common-mode signals at its input that were both of the same size, the common-mode signal would be 100 dB smaller than the desired signal at the output.