Patent ID: 8368575

Claim:
A pipeline type A/D converter, comprising: a sample-hold section for sampling and holding an analog signal; a plurality of A/D converting sections for converting the analog signal held by the sample-hold section into a plurality of digital signals; an arithmetic section for synthesizing the plural digital signals output from the plurality of A/D converting sections; and a control section for controlling operations executed by the plurality of A/D converting sections, wherein each of the plurality of A/D converting sections includes an A/D sub-converting section for converting an analog signal into a digital signal, a reference voltage generating section for generating a reference voltage corresponding to a converted result by said each of the plurality of A/D sub-converting sections, and a signal amplifying section for amplifying a differential signal between the reference voltage and the analog signal, wherein the signal amplifying section includes: N×M charge and discharge elements each having a capacitance C/N, where C denotes a prescribed capacitance of a positive integer, N denotes a prescribed division number of an integer equal to or greater than 2, and M denotes an amplification degree of the analog signal of an integer equal to or greater than 2; a switching element; and an operational amplifier, wherein the reference voltage generating section outputs the reference voltage obtained by multiplying a prescribed voltage by N, wherein at a sampling operation, the control section controls for sampling the analog signal by use of all of the N×M charge and discharge elements, and wherein at a holding operation, the control section controls for amplifying the analog signal to M times thereof by use of N charge and discharge elements out of all of the N×M charge and discharge elements, and for adding and subtracting the reference voltage obtained by multiplying the prescribed voltage by N to and from the analog signal amplified by use of remaining N×(M−1) charge and discharge elements.