Patent ID: 8009071

Claim:
A gain circuit comprising: a main amplification unit including: an amplifier; a first capacitor connected between a first input terminal of the gain circuit and a first input terminal of the amplifier; a second capacitor connected between the first input terminal of the amplifier and a first output terminal of the amplifier; and a first refresh unit including: a first refresh capacitor connected with a first terminal of the first refresh capacitor to a common node of the first refresh unit; and a second refresh capacitor connected with a first terminal of the second refresh capacitor to the common node of the first refresh unit; wherein the common node of the first refresh unit is arranged to be supplied with a reference voltage during a first phase of a refresh interval and connected to the first input terminal of the amplifier during a second phase of the refresh interval; a second terminal of the first refresh capacitor of the first refresh unit is arranged to be supplied with an input voltage of the gain circuit during the first phase of the refresh interval and connected to the first input terminal of the gain circuit during the second phase of the refresh interval; and a second terminal of the second refresh capacitor of the first refresh unit is arranged to be supplied with a first voltage, which is an output voltage or output reference voltage of the amplifier, during the first phase of the refresh interval and connected to the first output terminal of the amplifier during the second phase of the refresh interval.