Spice Modeling Of Decoupling Capacitor In Power Distribution Network

With the rapid development of the electric technology, the problem of PowerIntegrity becomes more and more serious. Its influence on the power of the chipsdetermines the quality of the entire design of the network. As a result, it is highlynecessary to solve the problem by means of simple and practical tools.The purpose of this paper is to develop a pre-simulation tool of power distributionnetwork. It enables engineers with solutions to the choice of proper decouplingcapacitors, so that, the chips on the circuit board can get pure power. There are twoparts: building the model and determining the type and the number of decouplingcapacitors. This paper mainly introduces the method of modeling of the decouplingcapacitors.Based on the structure of the power distribution network, this paper gives thedetailed analysis of the equivalent circuit of each part and their influence on the entiredistribution network. Then Spice models of decoupling capacitors were establishedseparately, using Monte Carlo method and vector fitting method. It proves that the Spicemodel established by vector fitting method is more precise. Then the compensativemethod of the impedance data was described. Finally, the pre-simulation tool of powerdistribution network is introduced. It proves that the precision of the Spice model ishigh and that the development needs are well met. The solution supplied by the PIpre-simulation tool dovetails nicely with the reality cases.