Patent ID: 8599053

Claim:
A gain amplifier comprising: a differential amplifier comprising first and second feedback capacitors and switches coupled in parallel to the first and second feedback capacitors wherein said switches are controlled by a control signal toggled at twice the frequency of a clock signal and a phase-shifted clock signal; a switched input stage having a first and second output coupled with the differential amplifier, comprising: first and second capacitors, a first input receiving a first signal of a differential input signal; a second input receiving a second signal of the differential input signal; a first plurality of switches controlled by the clock signal to connect the first terminal of the first capacitor with said first or second input, respectively and to connect the first terminal of the second capacitors with said second and first input, respectively; and a second plurality of switches controlled by the phase-shifted clock signal to connect the second terminal of the first capacitor with a first or second input of the differential amplifier and connecting the second terminal of the second capacitor with the second or first input of the differential amplifier.