A pair of complementary MOS transistors can be used as a signal limiter as is shown in the schematics to protect the input of an operational amplifier, ADC, or another sensitive device. The advantage of this limiter as compared to the diode-based limiter is the lower open-channel resistance of the MOS transistors as compared to a serial resistor in the diode-based limiter. This results in higher speed and lower thermal noise of the limiter.
