An Analytical Solution Method for Diode Circuits with Transcendental Schottky Equation

Abstract

Analytical solution to diode-containing circuits has been investigated for a long time, and many researchers have offered approximations using the Lambert-W function and numerical/iterative methods. However, a simple method without complex calculations and iterations has not been proposed in the literature. This paper proposes a two-step method to model a diode with the Schottky equation and solve the diode circuit with the transcendental equations. The proposed method depends on extracting two fitting coefficients using the LMS algorithm and utilizing them in a logarithm-based hand solution. The proposed solution method is applied to several multi-diode circuits and compared with the SPICE simulations. Diode currents in case studies are calculated by hand with no error by considering three digits after the comma. The proposed method is also compared with the state of art studies and tested with commercially available 40XX series diodes and 1N4532 high-speed diode. The method not only solves the transcendental diode equation but also characterizes the commercially available actual diodes. Case study results and comparisons with the studies in the literature prove the efficiency of the proposed hand solution method for the transcendental diode equation. Besides, the method brings a new approach to the straightforward solution of multi-diode circuits.