pH ISFET sensor with PVTA compensation

Sensory system performance and variability depend on the compensation degree against fabrication process, voltage, temperature and ageing (PVTA) variations. A pH ion sensitive field-effect transistor sensor with PVTA compensation is presented; stages for calibration and sensitivity adjustment were also included. To validate its performance, the proposed sensor was compared with a non-compensated sensor; the results showed that PVTA variations were reduced by 81.50% for fabrication process and ageing, 87.91% for voltage and 80.30% for temperature. The maximum resolution achieved was 833.33 mV/pH.