Patent ID: 7812877

Claim:
An I/F converter for generating a signal at a frequency corresponding to an amplitude of a current inputted to an input end, the I/F converter comprising switching means for selectively switching to either one of a first output end and a second output end to output the current inputted to the input end, a first capacitive element connected to the first output end of the switching means to accumulate charge corresponding to inputted current, first discharge means for discharging the charge accumulated in the first capacitive element, a first comparator portion connected at its input terminal to one end of the first capacitive element to compare amplitudes between a voltage at the one end of the first capacitive element and a reference voltage, the first comparator portion outputting from its output terminal a first comparison signal indicating a result of the comparison, a second capacitive element connected to the second output end of the switching means to accumulate charge corresponding to inputted current, second discharge means for discharging the charge accumulated in the second capacitive element, and a second comparator portion connected at its input terminal to one end of the second capacitive element to compare amplitudes between a voltage at the one end of the second capacitive element and a reference voltage, the second comparator portion outputting from its output terminal a second comparison signal indicating a result of the comparison, wherein when the switching means is set so that the switching means allows the current to be outputted to the first output end, the current inputted at the input end flows into the first capacitive element via the switching means, and when the switching means is set so that the switching means allows the current to be outputted to the second output end, the current inputted at the input end flows into the second capacitive element via the switching means.