AD CONVERTER

PROBLEM TO BE SOLVED: To provide an AD converter which is suitably used for the inverter control of a plurality of motors in different carrier cycles. SOLUTION: This AD converter is provided with: a first selector 5 for selecting either the U phase position information signal of a first motor and the U phase position information signal of a second motor; a second selector 6 for selecting either the V phase position information signal of the first motor and the V phase position information signal of the second motor; and first and second AD converters 3 and 4 for converting the outputs of the both selectors 5 and 6 into digital values. An overlap detection circuit 7 predicts whether the execution period of the next AD conversion of the U phase and V phase position information signals of the first motor and the performance period of the next AD conversion of the U phase and V phase position information signals of the second motor overlap in every carrier cycle, and notifies the AD controller 2 of the result of prediction. The AD controller 2 controls the operations of the both selectors 5 and 6 and the both AD converters 3 and 4 so that the execution of the next A/D conversion is mediated based on the prediction result. COPYRIGHT: (C)2008,JPO&INPIT