Patent ID: 7515086

Claim:
A multiplying digital-to-analog converter (MDAC) comprising: an amplifier that includes differential input terminals and differential output terminals; a first switched capacitor circuit coupled to a positive input terminal of the differential input terminals; and a second switched capacitor circuit coupled to a negative input terminal of the differential input terminals, each of the first and second switched capacitor circuits comprising: a feedback capacitor having a unit capacitance; a first capacitor that has a first capacitance, and includes a first common terminal coupled to a common terminal of the feedback capacitor and one of the differential input terminals; a second capacitor that has a second capacitance, and includes a second common terminal coupled to the common terminal of the feedback capacitor and one of the differential input terminals, the first capacitance corresponding to X times the unit capacitance, the second capacitance corresponding to (1−X) times the unit capacitance where X is a real number that is greater than 0 and less than 1; and a plurality of switches that connect input terminals of all of the capacitors to an analog differential input signal, and connect the differential input terminals to a common mode voltage during a first phase of a clock, and that disconnect the common mode voltage from the differential input terminals, connect an input terminal of the feedback capacitor to one of the differential output terminals, connect a first input terminal of the first capacitor to one of first, second and third reference voltages, and connect a second input terminal of the second capacitor to the second reference voltage during a second phase of the clock.