A thorough investigation into active and passive shielding methods for nano-VLSI interconnects against EMI and crosstalk

摘要

In this study two main shielding methodologies, active and passive, are comprehensively investigated for crosstalk and EMI alleviation. Electromagnetic coupling is a major concern for digital system wiring. It can cause logic fault, consume power and make signal integrity problem for neighbor wires. Active and passive shielding is employed to enclose partially some important wires like CLOCK network. Passive shield, which is a line connected to POWER rail or the GROUND, can enforce extra delay to the concerned wire. Rather, active shield is used to gain both guarding effect and reduction in time delay based on Miller's effect capacitance reduction. With area constraint for both silicon and metal, we have optimized which methodology should be chosen for best achievable performance. With simple analytic steps, the accuracy is verified and a design approach is introduced to choose the best. In addition, the immunity of the active and passive shield is studied against external electromagnetic wave. The result concludes that the passive shield show a better resistance in front of electromagnetic coupling, for both near pairing (crosstalk) and distant coupling (incident electromagnetic wave); in addition, active shielding method has better characteristic for timing issues. (C) 2015 Elsevier GmbH. All rights reserved.