Signal processing circuit comprising ion sensitive field effect transistor and method of monitoring a property of a fluid

摘要

A signal processing circuit includes an ion sensitive field effect transistor, a reference electrode for the ion sensitive field effect transistor, a metal oxide semiconductor transistor having its gate coupled to the reference electrode, and a biasing circuit. The biasing circuit is configured to bias the ion sensitive field effect transistor and the metal oxide semiconductor field effect transistor to operate in a weak inversion region and to provide an output current signal.