Design of Read-Out Circuit for Ion-Sensitive FET Using 45nm CMOS Technology Node

An efficient read-out circuit is essential for accurately interpreting signals from Ion-Sensitive Field Effect Transistors (ISFETs), which are used in applications such as chemical analysis, environmental monitoring, and medical diagnostics. This work presents the design of a high-performance read-out interface tailored to ISFETs, enabling precise signal acquisition, low noise, and enhanced sensitivity to ion concentration changes. The circuit incorporates advanced signal conditioning to minimize offset and drift, while ensuring compatibility with ISFET characteristics and stability under varying conditions. Optimized for low power consumption and compact size, the design is well-suited for portable and real-time sensing systems. This resulted in a reliable, scalable, and cost-effective solution that supports broader integration of ISFET technology into practicaland industrial applications. Conventional readout circuits use operational amplifiers, but this work replaces them with folded cascode amplifiers. The design achieves significantly low power consumption using a regulated cascode current mirror and 45 nm CMOS technology.