1. Op-Amps and Saturation

2. The Inverting Mode Op-Amp + - V1V1 VoVo RfRf R1R1 In theory, the gain of the op-amp is given by R f ÷ R 1. This equation works well until the output voltage increases too much. We must remember that the op-amp has a power supply. 0 V +V s -V s

3. By increasing the input voltage, we find that the output voltage is limited. The op-amp cannot give out any more than about 85% of the voltage it is being supplied with (±15 V). We say that the op-amp saturates.

4. Op-amp is saturated The gain equation works well on this part of the graph.

5. Saturation The op-amp will saturate if the input voltage is increased too much or if the gain is increased too much.