Patent ID: 7795944

Claim:
The low-offset input circuit comprising: an input circuit that receives a signal; an amplifier circuit that is connected to reflect a circuit characteristic variation that develops an offset voltage of the input circuit to an output; an adjusting section that adjusts the circuit characteristic variation of the input circuit according to an adjustment signal; a converter circuit that converts an output signal of the amplifier circuit into a digital signal; and a holding circuit that samples and holds one of the digital signal that has been converted by the converter circuit and a signal resulting from encoding the converted digital signal, wherein the amplifier circuit has a function of correcting the circuit characteristic variation of the amplifier circuit, and wherein the adjusting section corrects the circuit characteristic variation of the input circuit upon receiving the signal that is held by the holding circuit, wherein the amplifier circuit has a first state in which the amplifier circuit corrects the circuit characteristic variation of the amplifier circuit, and a second state in which the amplifier circuit reflects the circuit characteristic variation of the input circuit to an output, and wherein the holding circuit samples one of the digital signal and the encoded signal at a time when the amplifier circuit is brought in the second state, and the adjusting section corrects the circuit characteristic variation of the input circuit upon receiving a sampled retention signal.