Interface electronic device for reading an output signal and for controlling and conditioning a three-electrodes amperometric sensor

Abstract

Electronic devices and methods for reading an output signal and controlling a three-electrode electro-chemical amperometric sensor include an operational amplifier having a non-inverting input adapted to receive a biasing electric potential and an inverting input connectable to a reference electrode of the sensor. The devices further include one or more MOS transistors connected to the operational amplifier, with a first MOS transistor connectable to the collector electrode of the sensor to receive or supply a MOS transistor channel current representative of the cell current generated in the sensor, and a second MOS transistor connectable to a reference voltage by a conductor or a resistor. The resistance is lower than the cell impedance such that the current in the second MOS transistor channel depends on the current in the first MOS transistor channel through a nonlinear gain dependent on the resistor