Patent ID: 7389190
Filing Date: 2008-06-17
Classification: G01R

Abstract:
1. A comparator circuit that comprises: a sampler having a capacitor, said sampler sampling a measured signal by using a strobe pulse signal and its inversed strobe pulse signal that are both generated at a predetermined timing and applied thereto and outputting a sample voltage having a value of said measured signal at the predetermined timing charged in capacitor; and a comparator for comparing said sample voltage received from the capacitor of the sampler with a reference voltage and outputting a comparison result indicating whether said sample voltage is higher than said reference voltage; wherein said sampler comprises said diode-bridge switching circuit comprises the input side pair of diodes are connected in series with an input terminal at a junction therebetween to which the measured signal is applied; the output side pair of diodes are connected in series with an output terminal at a junction therebetween to which the capacitor is connected; a series connection of the input side pair of diodes and a series connection of the output side pair of diodes are connected in parallel between first and second terminals to which a reverse bias voltage is supplied so that the diode bridge switching circuit is normally maintained in an OFF state; and the strobe pulse signal applying circuit applies the strobe pulse signal and the inversed strobe pulse signal to the first and second terminals to render the diode bridge switching circuit in an ON state so that a value at the predetermined timing of the measured signal applied to the input terminal is derived from the output terminal and charged in the capacitor as a sample voltage of the measured signal.