COMPARATOR, DIFFERENTIAL AMPLIFIER CIRCUIT, AND ANALOG/DIGITAL CONVERTER

摘要

Disclosed is a comparator for performing comparison between an analog input signal and a comparison reference voltage at an analog/digital converter comprising a pre-amp unit constituted to include: a load carrying capacitor; a charge source; a transistor wherein a drain is connected to the load carrying capacitor and a source is connected to the charge source; and a compensation circuit wherein the analog input signal or the comparison reference voltage is input to an input terminal, and an output terminal is connected to a gate of the transistor. The compensation circuit detects and stores voltage information including information of an offset voltage in a reset period, and compensates the offset voltage using the stored voltage information in an amplifying period so as to be able to perform offset cancellation while maintaining low power consumption even if an MOS transistor is used as a driving element in a CS amplifier.