Operational Amplifier Input Modes
Single Input Inverting | Single Input Non-Inverting | Differential Input |
In the Inverting mode, the non-inverting input of the amplifier is grounded. An input signal is applied to the inverting input, and the output signal is 180° out of phase with the input signal.
In the Non-Inverting mode, the inverting input of the amplifier is grounded. An input signal is applied to the non-inverting input, and the output signal is in phase with the input signal.
In the Differential Input mode, the signal is applied to both of the input terminals. These signals have to be 180° out of phase and the output is going to be in phase with the non-inverting signal. In case the signals that are applied to both the inputs are in phase, there should be no output and that input signal is referred to as the Common mode signal. In all three of these modes, the op-amps are shown in an open-loop configuration, i.e. the outputs do not feedback to the op-amp inputs.