ANGLE DETECTION AD CONVERTER AND AD CONVERSION METHOD

摘要

PROBLEM TO BE SOLVED: To cancel the deterioration of accuracy that results from an offset in an angle detection AD conversion circuit when detecting an angle component from a two-dimensional analog signal on the basis of a successive approximation method. SOLUTION: A first bit is calculated according to a comparison result obtained by comparing an output signal calculated on the basis of a two-dimensional input signal from two magnetic sensors disposed at a rotator perpendicularly to each other, and a sine and a cosine corresponding to a first angle with a reference value. A second bit is calculated according to a comparison result obtained by comparing an output signal calculated on the basis of a value obtained by inverting the two-dimensional input signal and polarities of a sine and a cosine with the reference value. A third bit is calculated according to a comparison result obtained by comparing a third output signal calculated on the basis of the two-dimensional input signal and a second angle with the reference value. Whether the first bit is different from the second bit and the third bit is determined. COPYRIGHT: (C)2010,JPO&INPIT