Patent ID: 7224193

Claim:
A CV conversion circuit, comprising: an operational amplifier having an inverting input terminal and an output terminal connected to each other; a resistor having one end connected to a noninverting input terminal of the operational amplifier and the other end grounded; a first capacitor having one end connected to the noninverting input terminal of the operational amplifier and the other end connected to a first signal voltage source; a second capacitor having one end connected to the noninverting input terminal of the operational amplifier and the other end connected to an inverting output of the first signal voltage source; a third capacitor having one end connected to the noninverting input terminal of the operational amplifier and the other end connected to a second signal voltage source; and a fourth capacitor having one end connected to the noninverting input terminal of the operational amplifier and the other end connected to an inverting output of the second signal voltage source, wherein the first signal voltage source and the second signal voltage source generate signals in a time division manner, and a detection synchronous to the signals is carried out.