A Novel Electrical Circuit Model for Ion-Sensitive Field-Effect Transistor

An alternative electrical model for Ion-Sensitive Field-Effect Transistor (ISFET) sensors is presented in this work. The proposed model is worth to be employed in both DC and transient simulations where the behavior of the ISFET sensor coupled to its readout circuit can therefore be investigated. Whereas, previous models found in the literature could only be employed to perform DC simulations. The electrochemical stage of an ISFET is responsible to emulate the device's sensitivity to ion concentration. The alternative electrical model enables the representation of the ISFET electrochemical stage through a much simpler circuit topology than those found in the literature, without loss of generality. The simulation results employing the proposed ISFET model are compliant with those presented in the literature, asserting thus its effectiveness.