Shielding Methodologies in the Presence of Power/Ground Noise

Design guidelines for shielding in the presence of power/ground (P/G) noise are presented in this paper. The effect of P/G noise on crosstalk is analyzed for different line lengths, line widths, and interconnect driver resistances. Considering the P/G noise, a shield line can degrade rather than enhance signal integrity due to increased P/G noise coupling on the victim line. A 2π RLC interconnect model is used to investigate the effects of both coupling capacitance and mutual inductance on the crosstalk noise. Physical spacing and shield insertion are compared in terms of the coupling noise on the victim line for several technology nodes. Boundary conditions are also provided to determine the effective range of spacing and shield insertion in the presence of P/G noise. Additionally, the effects of technology scaling on P/G noise and shielding efficiency are discussed, and related design tradeoffs are addressed.