A Novel pH Sensor Current Mode Read-Out Circuit Using Operational Floating Current Conveyor

This paper presents a novel Ion Sensitive Field Effect Transistor (ISFET), as a pH sensor, read-out circuit that uses three Operational Floating Current Conveyors (OFCC). This read-out circuit provides a linear sensitivity to pH over a wide range (pH values 2-12). Moreover, it provides an output current that is linearly related to the measured pH. It uses only one type of active element (i.e. OFCC) that makes this circuit easier to be both integrated and fabricated using a conventional CMOS process. Our simulation results demonstrate that the read-out circuit works reliably and can be a suitable sensor read-out circuit for lab on a chip biomedical applications.