AD CONVERSION APPARATUS WITH CARRIER FREQUENCY REMOVING FUNCTION

摘要

PROBLEM TO BE SOLVED: To sufficiently remove carrier frequency components using a compact configuration. SOLUTION: An AD conversion apparatus is provided with an AD converter (1) including a voltage comparator (11) for comparing a first signal (S1) with a feedback signal (S2), and a voltage feedback circuit (12) for outputting the feedback signal (S2); a demultiplexer (2) of one-input N-output using the feedback signal (S2) as an input; an N-pieces of integrators (3) for integrating N-output signals of the demultiplexer (2); a multiplexer (4) of N-input one-output using each of outputs of the N-pieces of integrators (3); a subtractor (5) for outputting a difference between an analog signal Ai and an output signal of the multiplexer (4); an amplifier (6) for amplifying an output of the subtractor (5) to form a first signal (S1); and a switching control circuit (7) for circularly performing the input switching of the multiplexer (2) and the output switching of the demultiplexer (4) depending on carrier waves. COPYRIGHT: (C)2007,JPO&INPIT