Analysis of reverse voltage distribution of high-voltage diode stack considering effect of temperature

Abstract

In this paper, we proposed an equivalent circuit of a cell device (high-voltage silicon diode), considering effects of temperature and reverse voltage on it, and obtained the analytical expression of impedance of a cell device. Subsequently, in order to improve the reverse voltage distribution of the high-voltage diode stack consisting of a serial connection of cell devices, uniform voltage impedance was inserted in parallel with each cell device. Taking into account the impedance and the uniform voltage impedance of each cell device but also the leakage impedances connected to high-voltage terminal and ground terminal, the most generalized equivalent circuit of the high-voltage diode stack was newly proposed, from which the analytical expression on the reverse voltage applied to each cell device was obtained. Consequently, analyzing the ratio of the uniform voltage impedance to the impedance of a cell device and the non-uniformity of the reverse voltage distribution, the way to improve the reverse voltage distribution of the high-voltage diode stack was found, and it was verified experimentally. Finally, the possibility to estimate the reverse voltage distribution of the high-voltage diode stack quantitatively was supported by an analytical method, not experimental method.