PEAK-HOLD CIRCUIT, AND PEAK-HOLD METHOD

摘要

PROBLEM TO BE SOLVED: To hold a peak of a fast response signal with high accuracy.;SOLUTION: A peak-hold circuit includes: a constant current circuit CCC which receives a positive-polarity power-supply voltage at its one end and outputs a prescribed constant current from the another end; a current generation unit CG which has one end connected to an output of the constant current circuit CCC and receives a negative-polarity power-supply voltage at the another end and causes a prescribed current smaller than the constant current outputted from the constant current circuit CCC, to flow; a switch SW which has one end connected to the output of the constant current circuit CCC; a capacitor C which has one end connected to the another end of the switch SW and has the another end grounded; an operational amplifier AMP which has a first input connected to the another end of the switch SW and the one end of the capacitor C and has an output connected to a second input; and a comparator CMP which compares a voltage inputted to the first input, with an output voltage of the operational amplifier AMP inputted to the second input and controls the switch on the basis of the comparison result.;COPYRIGHT: (C)2015,JPO&INPIT