Patent ID: 7777663

Claim:
A discrete time amplifier circuit having a differential amplifier for amplifying a differential signal and a common-mode feedback circuit for feeding back the output voltage to said differential amplifier by receiving the output of said differential amplifier so that the output voltage is controlled to a reference voltage, wherein said common-mode feedback circuit comprises: a first switched-capacitor circuit being connected, by switching every ½ cycle, to a reference voltage source or the input/output terminals of said common-mode feedback circuit to repeat a sampling mode and a hold mode, a second switched-capacitor circuit being connected, by switching every ½ cycle, to said reference voltage source or said input/output terminals at a timing shifted by a ½ cycle from the switching timing of said first switched-capacitor circuit to repeat the sampling mode and the hold mode, and a common-mode feedback voltage generating circuit for generating and holding a common-mode feedback voltage using charges input from said first switched-capacitor circuit and said second switched-capacitor circuit.