Drift reduction in ion-sensitive FETs using correlated double sampling

A discrete-time technique, correlated double sampling (CDS), as a method to reduce drift during ion-sensitive field effect transistor (ISFET) operation is presented. The CDS technique exploits switched capacitors to resolve low-frequency signal errors such as drift and 1/f noise, which are generated by an ISFET and its readout. In conjunction with post-processing, experimental results confirm drift reduction using this technique.