A 36μW rail-to-rail-input chopper stabilized amplifier using correlated double sampling

This paper describes a chopper stabilized amplifier, obtained using an input chopper for modulation, an AC coupling for offset rejection and a correlated double sampling structure for demodulation, avoiding ripple spurs. The operational amplifier has a rail-to-rail input stage, with a supply voltage range from 1.8V to 5V. It is characterized by a multipath nested Miller compensation network with double pole-zero cancellation. The circuit achieves a simulated 130dB-dc-gain with a current consumption of 20μA, suitable for low-power application. Equivalent input offset has been evaluated by Montecarlo simulations demonstrating a maximum standard deviation of about 4μV.