A/D CONVERTER

摘要

PROBLEM TO BE SOLVED: To enhance accuracy of an A/D conversion which is lowered by parasitic capacitance of an analog input channel by using a plurality of analog input channels with one A/D converter. SOLUTION: Channel designation of the analog input switches 5-8 which connect the analog signal inputted from analog input terminals 1-4 to an A/D converter 13 is performed by an input channel designation register 10 and an increment circuit 11 and the analog input switches 5-8 are controlled by a decoder 9. Selection/storing of a conversion result outputted from the A/D converter 13 is performed by digital output switches 14-17, an output channel designation register 23 and an increment circuit 24 and the digital output switches 14-17 are controlled by the decoder 22.