Patent ID: 8330499
Filing Date: 2012-12-11
Classification: H03K

Abstract:
1. A comparator circuit having a differential amplifier, the comparator circuit making a logical judgment by comparing an input voltage with a reference voltage, generating and outputting an output voltage of a result of the logical judgment, the comparator circuit comprising: a current source, that generates and supplies bias current of a predetermined minute current to the differential amplifier; a first inverter circuit, that inverts a differential voltage from the differential amplifier and outputs an inverted signal; and an adaptive bias current generator circuit, that detects the bias current of the current source, and detects a through current of the first inverter circuit, wherein the adaptive bias current generator circuit generates and supplies an adaptive bias current for executing adaptive bias current control to the differential amplifier, based on the detected bias current and the detected through current, so as to allow the differential amplifier to operate with the bias current for a time interval of no logical judgment executed by the differential amplifier, and to allow the differential amplifier to operate by using the adaptive bias current obtained by increasing the bias current for a time interval of logical judgment executed by the differential amplifier.