A single-chip ISFET based pH sensor

In this paper, a differential p-channel ion-sensitive field-effect transistor (ISFET) based pH sensor is presented. The sensor has been implemented in a 180nm 1-poly 6-metal standard CMOS process. The sensor uses a larger sensing gate area for improved sensitivity. Simulation results show that the designed single-chip ISFET based pH sensor provides an ISFET sensitivity of 50 mV/pH over a 1–14 pH range with 31.3 μW of power.