Voltage Regulator Module Noise Analysis for High-Volume Server Applications

This paper presents a methodology to analyze voltage regulator module (VRM) noise coupling problems in high-volume server applications. The technique is applied on a real engineering design. The comprehensive model includes irregular power shapes, decoupling capacitors, and dielectric and conductive loss. Irregular shaped power plane modeling is cross-checked with four separate methods to demonstrate accuracy

Statistical design, analysis, and diagnosis of digital systems and embedded RF circuits

Ph.D.Madhaven Swaminatha

Analysis of Noise Coupling Result from Overlapping Power Areas within Power Delivery Networks

Large area fills or entire planes constitute the backbone of the power delivery network in multi-layer printed circuit boards (PCBs). The overlapping of power areas at different voltages, though, may cause coupling among them. Full wave methods can be used to model these types of structures, and the coupling effect can be accurately analyzed by means of the finite element method (FEM), finite difference time domain (FDTD) and others. However, full wave methods are usually time consuming. In this paper, a cavity model approach is proposed to analyze the noise coupling among plane pairs in multi-layer configurations. The cavity model has analytical expressions for the impedance (Z) matrix associated with ports defined on regularly-shaped planar circuits and it is computationally efficient. The combination of such an approach with the segmentation method allows the extension of the analysis to irregularly shaped and multi-layer structures. A multi-layer PCB with three power planes is analyzed in this article by means of the proposed cavity model approach as well as a full wave FEM method. A comparison between the simulation results obtained with the two different methods is finally provided