The acronym NOD stands for Nonlinear Ohmic Device. Ever since the advent of devices like diodes and transistors [1], the ideas of nonlinear and non-ohmic resistances (those which don’t follow Ohm’s law) have become synonymous [2]. In our recent research endeavors [3-4] we showed that the idea of nonlinear devices being always non-ohmic is misconceived and Ohm’s law should rather be applicable to all resistive nonlinear devices and circuits. Based on a research on modification of the general diode equation [4], an interpretation of the Ohm's law is drawn so that it can be applied to nonlinear circuits as well [3]. Additionally, the physics behind the important phenomenon of induced change in resistance (ICR) [3], that enables the use of Ohm’s law in semiconducting junction devices, is explained and its inclusion is made in the equations for circuit design and analysis.

The modification of the general diode equation [4] is expected to bring a positive disruption in the modeling of semiconductor devices as it disproves and changes the fundamental equation of semiconductor devices given by the Nobel Laureate, William Shockley. This change removes the major bottleneck of non-ohmic devices and brings correct use of pre-established physics and circuit laws whereby accurate, fast and large signal analytical/semi-analytical models of nonlinear electronic devices can be made for their use in circuit analysis, design and simulation. The current ‘state of the art’ models are usually paralyzed by heavy use of computationally inefficient empirical equations that are bereft of any physical insight and are incompatible with basic circuit laws. This project is expected to remove such inefficiencies and incompatibilities.

The project is targeted at establishing a class of electronic devices which may be called ‘nonlinear ohmic devices’ (NODs). Development of NOD models for various devices like diodes and transistors shall be taken up and their SPICE compatible parameters shall be made available. Eventually, this project will aim at developing ohmic models for all nonlinear responses of resistive devices.

Various resources like publications, videos, tutorials and tools pertaining to NODs shall be made available in this website from time to time for students, researchers, academics and industries who are interested in this.


[1] W. Shockley, "The theory of p-n junctions in semiconductors and p-n junction transistors," The Bell System Technical Journal, vol. 28, no. 3, pp. 435-489, July 1949

[2] J.-M. Yu et al, "Triple-Node FinFET with Non-Ohmic Schottky Junctions for Synaptic Devices," IEEE Electron Device Letters, vol. 44, no. 1, pp. 40-43, Jan. 2023.

[3] Pragnan Chakravorty, “Some Analytical Perspectives of Nonlinear Circuits,” IEEE TechRxiv, July 2022

[4] Pragnan Chakravorty, “A Modified General Diode Equation”, IEEE Transactions on Computer Aided Design of Integrated Circuits and Systems, vol. 41, no. 08, pp 2763-2767, September 2021.