Patent ID: 7919959

Claim:
A signal readout circuit of an amperometric sensor, comprising: a first electrode, a second electrode, a third electrode; a first amplifier, having a first input terminal, a second input terminal, and an output terminal, wherein a voltage is input from the first input terminal, and the second input terminal is electrically connected to the second electrode; a second amplifier, having a first input terminal, a second input terminal, and an output terminal; a first transistor, having a gate, a drain, and a source, wherein the gate and the drain are connected to the first input terminal of the second amplifier, and the source is connected to a ground terminal; a second transistor, having a gate, a drain, and a source, wherein the gate is electrically connected to the gate of the first transistor, the drain is electrically connected to the second input terminal of the second amplifier, and the source is connected to the ground terminal; a third transistor, having a gate, a drain, and a source, wherein the gate is electrically connected to the output terminal of the first amplifier, the source is electrically connected to the third electrode, and the drain is electrically connected to the drain of the first transistor; and a fourth transistor, having a gate, a drain, and a source, wherein the gate is electrically connected to the output terminal of the second amplifier, the drain is connected to a load, and the source is electrically connected to the drain of the second transistor.