1,721,006 research outputs found
An approach to computer simulation of bonding and package crosstalk in mixed-signal CMOS ICs
No full textThis paper presents an approach for simulation of mixed analog-digital CMOS integrated circuits, aiming at estimating crosstalk effects due to current pulses drawn from voltage supplies. A simple expression of voltage and current in the pull-up and the pull-down of a CMOS logic gate is derived, and a representation of digital switching noise in time domain can be easily calculated through a dedicated computer program. This representation is used to perform an analog simulation using SPICE, to evaluate the propagation of the switching noise through the parasitic elements of the package and of the bonding wires. Simulation results for two case studies are presented
An analysis of current waveforms in CMOS logic cells for RF mixed circuits
No full textThis paper presents an approach for simulation of mixed-signal CMOS integrated circuits, aiming at estimating crosstalk effects, by identifying possible sources of disturbances in analog-digital integrated systems, such as current pulses drawn from voltage supplies. A simple expression of voltage and current in the pull-up and the pull-down of a CMOS logic gate can be derived. A computer program demonstrates the feasibility of the proposed approach, and a representation of digital switching noise in frequency domain has been derived
Properties of digital switching currents in fully CMOS combinational logic
No full textIn this paper, we present a model to derive statistical properties of digital noise due to logic transitions of gates in a fully
CMOS combinational circuit. Switching activity of logic gates in a digital system is a deterministic process, depending on both circuit parameters and input signals. However, the huge number of logic blocks in a complex IC makes digital switching a cognitively stochastic process. For a combinational logic network, we can model
digital switching currents as stationary shot noise processes, deriving both their amplitude distributions and their power spectral densities. From the spectra of digital currents, we can also calculate
the spectral components and the rms value of disturbances injected into the on-chip power supply lines. The stochastic model for switching currents has been validated by comparing theoretical results with circuit simulations
Simulation of mixed-signal circuits for crosstalk evaluation
No full textThis paper presents an approach for simulation of mixed-signal circuits, analyzing possible sources of disturbances in analog-digital integrated systems, such as current pulses drawn from voltage supplies. A closed-form expression of voltage and current in the pull-up and the pull-down of a CMOS logic gate can be derived. A computer program demonstrates the feasibility of the proposed approach. Simulation results of a non-overlapped two-phase clock generator are presented
Simulation of crosstalk through bonding and package in mixed-signal CMOS ICs
No full textThis paper presents an approach for the simulation of mixed-signal CMOS integrated circuits, aiming at estimating crosstalk effects, by identifying possible sources of disturbances in analog-digital integrated systems, such as current pulses drawn from voltage supplies. A simple expression of voltage and current in the pull-up and the pull-down of a CMOS logic gate can be derived. A computer program demonstrates the feasibility of the proposed approach, and a representation of digital switching noise in time domain has been derived. This representation has been used to perform an analog simulation using SPECTRE, to evaluate the propagation of the switching noise through the parasitic elements of the package and of the bonding wires
Effects of digital switching noise on analog circuits performance
No full textIn this paper, we discuss generation of digital switching noise and its propagation through substrate and interconnection parasitics. Effects of switching noise on analog voltage references and radio-frequency blocks are presented. Both simulated and measured results confirmed that crosstalk effects are strongly dependent on substrate and package type. Isolation strategies must be specifically designed for a mixed-signal chip, as they could even worse crosstalk if they are not properly designed accounting for values of parasitics
Digital switching noise as a stochastic process
No full textSwitching activity of logic gates in a digital system is a deterministic process, depending on both circuit parameters and input signals. However, the huge number of logic blocks in a digital system makes digital switching a cognitively stochastic process. Switching activity is the source of the so-called "digital noise", which can be analyzed using a stochastic approach. For an asynchronous digital network, we can model digital switching currents as a shot noise process, deriving both its amplitude distribution and its power spectral density. From spectral distribution of digital currents, we can also calculate the spectral distribution and the power of disturbances injected into the on-chip power supply lines
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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