Patent ID: 6362770
Filing Date: 2002-03-26
Classification: H03M

Abstract:
A switched capacitor gain stage having a first and second input and an output, the switched capacitor gain stage comprising:(a) an amplifier having an output connected to the output of the gain stage; (b) a first capacitor pair; (c) a second capacitor pair; (d) a third capacitor pair; (e) a switch network operating to: (i) at a first time, switch the first capacitor pair and the second capacitor pair to receive varying voltages from the first and second inputs, respectively, and switch the third capacitor pair across the amplifier and a reference voltage to provide an amplifier output voltage equal to a gain factor times a voltage previously received on the third capacitor pair plus the reference voltage; (ii) at a second time after the first time switch the first capacitor pair across the amplifier and a reference voltage to provide an amplifier output voltage equal to a gain factor times the voltage previously received on the first capacitor pair plus the reference voltage; and (iii) at a third time after the second time switch the first capacitor pair and the third capacitor pair to receive varying voltages from the first and second inputs, respectively, and switch the second capacitor pair across the amplifier and a reference voltage to provide an amplifier output voltage equal to a gain factor times the voltage previously received on the second capacitor pair plus the reference voltage; whereby the first and second inputs are sampled simultaneously and output sequentially.