Patent ID: 7023266

Claim:
A device for nullifying an offset voltage in an operational amplifier, the operational amplifier having a first input, a second input, an output, and a first resistor connected between the output and the first input, the device comprising: an adjustable resistor electrically connected to the first resistor, forming a first resistor network having a first feedback ratio at the first input of the operational amplifier; a comparator having a first input and a second input, the first input electrically connected to the output of the operational amplifier through a second resistor; a third resistor connected to the second resistor, forming a second resistor network having a second feedback ratio at the first input of the comparator; and an offset measurer electrically connected to the comparator and the adjustable resistor for measuring an output value of the comparator and for adjusting the adjustable resistor based on the measured output value.