Power Integrity in Advanced Design System (ADS)
应用文章
What are the high frequency characteristics of a real capacitor?
Capacitors are widely used in power distribution network (PDN) designs. The equivalent circuit of a real capacitor is an ideal capacitor in series with an inductor and a resistor as shown in Figure 1. At low frequency, behavior of a real capacitor is close to an ideal capacitor as shown in Figure 2. As the frequency is going higher to self resonant frequency, the capacitor behavior deviates from an ideal capacitor. When frequency is higher than self resonant frequency, the capacitor is more like an inductor than a capacitor. Therefore it is important to understand the self resonant frequency of a capacitor before using the capacitor in PDN designs.