Patent ID: 7589660

Claim:
A sample and integrate circuit, comprising: a first switching device that has first and second states and that includes a first terminal that communicates with a first input voltage when the first switching device is in the second state and that communicates with a first voltage reference when the first switching device is in the first state; a first capacitance that includes a first end that communicates with a second terminal of the first switching device; a second capacitance; a second switching device that has first and second states and that includes a first terminal that communicates with a second input voltage when the second switching device is in the first state and that communicates with a second voltage reference when the second switching device is in the second state; a third capacitance that includes a first end that communicates with a second terminal of the second switching device; a fourth capacitance; and an amplifier that has a first input that communicates with a second end of the first capacitance and a first end of the second capacitance and a second input that communicates with a second end of the third capacitance and a first end of the fourth capacitance.