Patent ID: 7902916

Claim:
A switched capacitor resonator, comprising: a main input terminal configured to receive an analog differential signal, and a main output terminal configured to output an analog differential signal; a first signal input circuit connected to the main input terminal, and having a switched capacitor circuit configuration configured with a capacitor and two kinds of switches configured to be opened/shorted by switching clocks having a phase different of 180° therebetween; a first integrator circuit comprising a first differential operational amplifier having an input terminal connected to the first signal input circuit, and a first sub feedback circuit having the switched capacitor circuit configuration, the first sub feedback circuit being connected between input and output terminals of the first differential operational amplifier; a second signal input circuit connected to the output terminal of the first differential operational amplifier, and having the switched capacitor circuit configuration; a second integrator circuit comprising a second differential operational amplifier having an input terminal connected to the second signal input circuit and an output terminal connected to the main output terminal, and a second sub feedback circuit having the switched capacitor circuit configuration, the second sub feedback circuit being connected between input and output terminals of the second differential operational amplifier; and a main feedback circuit connected between the first signal input circuit and the main output terminal, and having the switched capacitor circuit configuration, wherein the main feedback circuit has a capacitor including a first end and a second end; and wherein the first end is directly connected to the first signal input circuit and directly connected to the input terminal of the second differential operational amplifier through the switches, and the second end is directly connected to the main output terminal through the switches, whereby the capacitor of the main feedback circuit serves as an integration capacitor connected between the input and output terminals of the second differential operational amplifier according to whether the switches are shorted or opened.