Equivalent-Circuit Model for High-Capacitance MLCC Based on Transmission-Line Theory

Abstract

This paper provides a modeling methodology for high-capacitance multilayer ceramic capacitors (MLCCs) based on the transmission-line theory. To model the high-capacitance MLCC comprised of hundreds of thin layers, a distributed equivalent circuit is modified to a transmission-line circuit. Simpler models for MLCCs are demonstrated using a continued fractions approximation from the transmission-line input impedance equation. A second-order model predicts MLCC characteristics up to the first self-resonant frequency, and a fourth-order model corresponds more accurately to the MLCC behavior up to 100 MHz. In addition, model parameters are extracted using the measured impedance and physical dimension data without optimization.