Voltage subtracting circuit carrying out voltage subtraction by converting input voltage into current, intensity detecting circuit, and semiconductor integrated circuit device using the same

摘要

A voltage subtracting circuit includes a conversion circuit, a holding circuit, and a differential voltage generator. The conversion circuit converts a first voltage input during a first period into a first current proportional to the first voltage. The conversion circuit further converts a second voltage input during a second period following the first period into a second current proportional to the second voltage. The holding circuit holds the first current during the first period as a third voltage. The holding circuit further outputs the first current during the second period on the basis of the third voltage. The differential voltage generator outputs a differential voltage between the second voltage and the first voltage during the second period on the basis of the second current output by the conversion circuit and the first current output by the holding circuit.