A Novel Conditioning Circuit for Floating-Gate ISFET Bio-Sensor

Abstract

Floating-Gate-Ions-Sensitive-Field-Effect-Transistors (FG-ISFETs) are becoming the sensor’s platform for various fields such as biomedical and chemical sensors. Despite many advantages like quick response, small size as well as wide measurement range, the efficiency of the output measurement is widely affected by temperature, This requires more safety in the measured results and the analysis’s tools. This study describes a novel integrated circuit that improves the thermal stability of the output signal of the ion-sensitive field effect transistors (ISFETs). After that, we investigate the temperature dependency of the FG-ISFET using the mentioned macro model and we shows that the temperature coefficient is about of 6 mV/°C. Afterward, a new integrated interface circuit that can perform great temperature compensation was developed. This operation aims to enhance stability of readout circuit for FG-ISFET. The achieved result of the FG-ISFET under different simulations shows that the readout circuit has a good temperature compensation i.e. :2.4 〖10〗^(-9) mV/°C.