- Ideal OP Amp Definition: An ideal OP Amp is defined as a differential amplifier with infinite open loop gain, infinite input resistance, and zero output resistance
- Infinite Input Resistance: Ideal OP Amps have infinite input resistance, which leads to zero input current.
- Zero Output Resistance: Ideal OP Amps have zero output resistance, ensuring maximum efficiency in signal transmission.
- Infinite Bandwidth: Ideal OP Amps can operate at any frequency range due to their infinite bandwidth.
- Zero Offset Voltage: Ideal OP Amps have zero offset voltage, meaning there is no voltage difference between the input terminals.
What is an Ideal OP Amp?
An operational amplifier (OP Amp) is defined as a direct current coupled voltage amplifier that increases the input voltage passing through it. Ideally, an OP Amp should have high input resistance, low output resistance, and very high open loop gain. In an ideal OP Amp, the input resistance and open loop gain are infinite, while the output resistance is zero.
An ideal OP amp has have following characteristics—
| Characteristic | Value |
| Open Loop Gain (A) | ∝ |
| Input Resistance | ∝ |
| Output Resistance | 0 |
| Bandwith of Operation | ∝ |
| Offset Voltage | 0 |
An ideal OP Amp is defined as a differential amplifier with infinite open loop gain, infinite input resistance, and zero output resistance.
The ideal OP Amp has zero input current because its infinite input resistance creates an open circuit at the input. This means there is no current at either input terminal.
With no current through the input resistance, there is no voltage drop between the input terminals. Thus, no offset voltage appears across the inputs of an ideal operational amplifier.
If v1 and v2 are the voltages at the inverting and non-inverting terminals of the OP Amp, and v1 = v2, then in an ideal case:
The bandwidth of operation of an ideal op-amp is also infinite. That means the op-amp perform its function for all ranges of frequencies of operation.
