Nur Liyana Mardhiah, Lee Yoot Khuan, Roziah Jarmin
ISFET, LTSPICE IV, H+ Ion, pH
pH measurement has been reported in many applications as a key parameter, such as clinical analysis, food production, biotechnology processes, wastewater treatment, environmental and life sciences. Advances in FET technology introduces a chemical effect transistor, the Ion Selective Field Effect Transistor (ISFET), which can convert the activity of ions in electrolyte into electrical potential. It has the potential of an integrated detection system. It is cost effective if design of such a measurement system can be assessed and improved using a simulator such as LTSPICE, before the costly fabrication. However, the ISFET macromodel is not listed as a component in the LTSPICE IV component library. Our work here describes the development of an ISFET macromodel in LTSPICE IV. It started with derivation of the mathematical models, building of the netlist and explanation on the procedure to include as library component. From simulation result, the drain current is found to vary with pH, arises from the variation in the concentration of the H+ ion. Low pH or acidic solution produces high value of Id, when concentration of H+ ion concentration is high in the electrolyte solution.
Cite this paper
Nur Liyana Mardhiah, Lee Yoot Khuan, Roziah Jarmin. (2016) LTSPICE IV Simulation of H+ Ion FET. International Journal of Chemistry and Chemical Engineering Systems, 1, 70-75