System-level Signal Integrity Research Articles

Signal Integrity and Power Integrity Issues at System Level

System-level signal integrity (SI) and power integrity (PI) problems are taken into account. System-level simulation of high-speed systems with effect of external environment is described. SI and PI issues with complete analysis of package, board, termination, squid card, and decoupling network are shown. Common problems of simulations-passivity violation, stability, causality, and interoperability, are also discussed.

Efficient Modeling of Rerouted Return Currents in Multilayered Power-Ground Planes by Using Integral Equation

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Multilayered power-ground (PG) planes are commonly used to supply power to circuits in high-speed electronic packages and printed circuit boards (PCBs). In this paper, we propose an efficient integral equation equivalent network method to simulate the interference produced by the rerouted return currents of signal traces inside such PG planes. The integral equation is created based on the geometrical features of the PG planes. Therefore, it could reduce the computing time and will be maintaining good accuracy. By discretizing the integral equation, a multiport equivalent network model is derived for each layer of the PG planes. Their [<formula formulatype="inline"> <tex>$Z$</tex></formula>] matrices are then obtained. These [<formula formulatype="inline"> <tex>$Z$</tex></formula>] matrices can be smoothly integrated with signal traces and other circuit models of lumped components mounted in the package and on the PCB, so that the system-level signal integrity and power integrity can be simulated efficiently. </para>

Perturbation Schemes for Passivity Enforcement of Delay-Based Transmission Line Macromodels

This paper introduces two different algorithms for passivity enforcement of transmission-line macromodels based on the generalized method of characteristics (MoC). The first scheme corrects passivity violations via perturbation of purely imaginary solutions of a nonlinear Hamiltonian eigenvalue problem. The second scheme is based on a linearly constrained quadratic optimization formulated at carefully selected frequency samples. Both schemes can be viewed as extensions to the case of MoC-based macromodels of existing techniques that were only available for lumped macromodels. The resulting passive delay-based macromodels can be safely employed in system-level signal integrity simulations, due to their inability to produce any spurious energy gain. Several numerical examples illustrate the behavior of both schemes on transmission line structures of practical interest, highlighting their main differences and the open problems deserving further research work.

Linear and Nonlinear Macromodels for System-Level Signal Integrity and EMC Assessment

Summary This paper presents a systematic methodology for the system- level assessment of signal integrity and electromagnetic compatibility effects in high-speed communication and information systems. The proposed modeling strategy is illustrated via a case study consisting of a critical coupled net of a complex system. Three main methodologies are employed for the construction of accurate and efficient macromodels for each of the sub-structures typically found along the signal propagation paths, i.e. drivers/receivers, transmission-line interconnects, and interconnects with a complex 3D geometry such as vias and connectors. The resulting macromodels are cast in a common form, enabling the use of either SPICE-like circuit solvers or VHDL-AMS equation-based solvers for system-level EMC predictions.

Statistical Signal Integrity Analysis and Diagnosis Methodology for High-Speed Systems

This paper discusses an efficient statistical analysis methodology for system-level signal integrity analysis. In the proposed method, statistical variations of the design and operational parameters are mapped to system performance through simulations based on orthogonal Taguchi arrays. Using the sensitivity functions derived from these simulations, statistical distributions of the performance measures are computed. The sensitivity functions and probability distributions of the design parameters are utilized as a diagnosis tool to estimate the design parameters of a system for a given measured performance. The statistical methodology is applied for design space exploration to improve system performance. For demonstrating the concept, a source synchronous memory bus and a peripheral input-output (I/O) bus have been analyzed under design and operational variations.

System-Level Reliability Assessment of Mixed-Signal Convergent Microsystems

The next-generation convergent microsystems, based on system-on-package (SOP) technology, require up-front system-level design-for-reliability approaches and appropriate reliability assessment methodologies to guarantee the reliability of digital, optical, and radio frequency (RF) functions, as well as their interfaces. Systems approach to reliability requires the development of: i) physics-based reliability models for various failure mechanisms associated with digital, optical, and RF Functions, and their interfaces in the system; ii) design optimization models for the selection of suitable materials and processing conditions for reliability, as well as functionality; and iii) system-level reliability models understanding the component and functional interaction. This paper presents the reliability assessment of digital, optical, and RF functions in SOP-based microsystems. Upfront physics-based design-for-reliability models for various functional failure mechanisms are presented to evaluate various design options and material selection even before the prototypes are made. Advanced modeling methodologies and algorithms to accommodate material length scale effects due to enhanced system integration and miniaturization are presented. System-level mixed-signal reliability is discussed thorough system-level reliability metrics relating component-level failure mechanisms to system-level signal integrity, as well as statistical aspects.