Patent ID: 8610615
Filing Date: 2013-12-17
Classification: H03M

Abstract:
1. An A/D conversion integrated circuit including a plurality of A/D converters; each A/D converter comprising: an input for receiving an analog signal to be A/D converted; an output for providing at least a part of a digital signal having a predetermined number of bits representing the analog signal; a sub-A/D conversion circuit for generating a sub-digital signal representing one or a plurality of bit values in the digital signal in response to the analog signal and feeding the sub-digital signal to the output; an RTZ waveform generator circuit, connected to an output of the sub-A/D conversion circuit for generating an RTZ signal having modulated the sub-digital signal; a D/A conversion circuit; a switched-capacitor amplifier circuit comprising a plurality of capacitors, a switching device, and an arithmetic amplifier circuit, at least one of the capacitors being connected to a virtual grounding terminal of the arithmetic amplifier circuit through the switching device; and an RTZ signal receiving circuit, including a memory circuit for holding a signal encoding the RTZ signal to a digital signal, for outputting the output of the memory circuit to the D/A conversion circuit; wherein the RTZ signal of the RTZ waveform generator circuit is constituted by a waveform including the same number of transitions from a first voltage level to a second voltage level and from the second voltage level to the first voltage level in a period when the switching device connected to the virtual grounding terminal of the arithmetic amplifier circuit keeps a state thereof unchanged.