Crosstalk pulsewidth calculation

doi:10.1016/j.mejo.2009.05.004

Microelectronics Journal

Volume 41, Issue 8, August 2010, Pages 474-479

https://doi.org/10.1016/j.mejo.2009.05.004 Get rights and content

Abstract

Generally, it is better to use closed form expressions instead of simulation tools to predict coupling effects in a circuit and evaluate noise voltages characteristics. A new RLC crosstalk noise expression, based on an RLC transmission line model propagating each propagation mode, has recently been proposed and has been validated in previous works. From this expression, we propose in this paper to calculate the noise characteristics such as the maximum amplitude and the noise pulsewidth. They provide information on the way to modify the circuit structures or interconnect designs to reduce or control crosstalk noise more rapidly than by setting about electrical simulations.

Section snippets

Introduction and background

Advancements in the field of VLSI have lead to a decrease in device geometries, high device densities, high clock rates and small signal transition times. Thus, interconnection lines that were once considered to be electrically isolated can now interfere with each others and have an important impact on system performances. One such interaction caused by parasitic couplings between wires is known as crosstalk. A number of simple crosstalk noise models have been proposed in literature. Refs. [1],

Maximum crosstalk evaluation

The inductive contribution on crosstalk voltage is always smaller than the capacitive one in VLSI circuits due to the high interconnection resistance. In this paper, we neglect the inductive coupling and focus exclusively on capacitive crosstalk voltage V_C. We have shown in [7] that it is possible to liken a distributed coupled-line RC system crosstalk waveform with a lumped RC system by using a correlation method (similar to a model order reduction method). Comparisons between simulated and

Determination of V_C_max/2 times t₁ and t₂

Let Np_C be the capacitive crosstalk voltage pulsewidth taken at V_C_max/2. It can be calculated according to the following relation: Np_C=t₂−t₁. The capacitive crosstalk voltage V_C reaches V_C_max/2 at t₁ and t₂. Since we correlate the distributed crosstalk waveform with the analytical one, calculate Np_Ceq consists in determining in the time domain the solutions of the following equation: $V_{C_{eq}} (t_{1_{eq}}, t_{2_{eq}}) = \frac{V_{in}}{2} [e^{(- (t_{1_{eq}, 2_{eq}} - Δ t_{oeq}) / τ_{oeq})} - e^{(- (t_{1_{eq}, 2_{eq}} - Δ t_{eeq}) / τ_{eeq})}] = \frac{V_{C_{eq} \max}}{2}$

However, it is not possible to

Spice simulation comparisons

From the analytical expressions (16), (19), we verify if the new times t₁ and t₂ calculated values are more or less accurate than the former ones leading to a better knowledge of the pulsewidth/critical timing interval when crosstalk voltage must be taken into account to assure the signal transmitted integrity and propagation along the lines. A lot of validations have been realized to verify the two expressions viabilities. Some of them are presented in this paper.

Comparisons Tables (Table 2,

Conclusion

In this paper, we propose analytical expressions to calculate very accurately capacitive noise voltages characteristics such as the maximum voltage amplitude and the noise pulsewidth taken at maximum amplitude half height which corresponds to the critical time domain when the coupling effects must be taken into account. All these expressions have been deduced from the correlation method/model order reduction method we presented in previous works; this method allowing to assimilate a distributed

Reference (8)

K. Shepard, et al., Globalharmony: Coupled Noise Analysis for Full-Chip RC Interconnect Networks, in: Proceedings of...
P. Heydari, M. Pedram, Capacitive Coupling Noise in High-Speed VLSI Circuits, in: IEEE Transactions On CAD of...
J. Cong, D. Zhigang Pan, P.V. Srinivas, Imporved Crosstalk Modeling for Noise Constrained Interconnect Optimization,...
R. Suaya, Interconnect Modeling for High Speed Digital Circuits-the Role of RLC Coupling, in: Proceedings of MSM 2002,...

There are more references available in the full text version of this article.

Cited by (2)

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2012, Wuli Xuebao/Acta Physica Sinica
Accurate analytical model for single event (SE) crosstalk
2012, IEEE Transactions on Nuclear Science

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