Reducing Noise and/or Power Consumption in a Switched Capacitor Amplifier Sampling a Reference Voltage

摘要

An aspect of the present invention ensures that (substantially) equal common mode voltage is present at the input terminals of an operational amplifier (amplifying the residue signal in a stage of an ADC in two phases) while reducing the noise introduced into the amplified signal. Such a features is obtained by using a first reference capacitor which is coupled between an input terminal of the operational amplifier and a reference voltage in a first phase, and between the input terminal and a the reference voltage but with opposite polarity in the second phase.