Development and Validation of a Microcontroller Model for EMC

Models of integrated circuits (ICs) allow printed circuit board (PCB) developers to predict radiated and conducted emissions early in board development and allow IC manufactures insight into how to build their ICs better for electromagnetic compatibility (EMC). A model of the power delivery network, similar to the ICEM or LECCS model, was developed for a microcontroller running a typical program and used to predict the noise voltage between the power and return planes of a PCB. The IC and package model was generated using the Apache tool suite. A model of the PCB was created using an electromagnetic cavity model and lumped-element models of components on the board. Values of predicted and measured impedance looking into the IC and PCB matched within a few dB from a few 10s of MHz up to 1 GHz. Measured and predicted values of noise voltage matched within about 6 dB at clock harmonics up to 600-700 MHz

Application of Chip-Level EMC in Automotive Product Design

Integrated circuits (ICs) are often the source of the high-frequency noise that drives electromagnetic emissions from electronic products. A case study is presented where emissions from a printed circuit board containing an automotive microcontroller are reduced significantly through analysis of the coupling mechanisms from the chip to the board and attached cables. Noise generated by the IC is explored through measurements in a semi-anechoic chamber and TEM cell, through near-field scans, and through modifications to the printed circuit board. Noise is driven by the IC through both power and I/O connections. Results show that a ferrite in series with I/O power in this application reduced emissions by 10 dB or more at critical frequencies. Possible causes for emissions from the IC and modifications that might reduce these emissions are discussed

Development and validation of a microcontroller model for EMC

Abstract-Model

A global database of nitrogen and phosphorus excretion rates of aquatic animals

International audienceAnimals can be important in modulating ecosystem-level nutrient cycling, although their importance varies greatly among species and ecosystems. Nutrient cycling rates of individual animals represent valuable data for testing the predictions of important frameworks such as the Metabolic Theory of Ecology (MTE) and ecological stoichiometry (ES). They also represent an important set of functional traits that may reflect both environmental and phylogenetic influences. Over the past two decades, studies of animal-mediated nutrient cycling have increased dramatically, especially in aquatic ecosystems. Here we present a global compilation of aquatic animal nutrient excretion rates. The dataset includes 10,534 observations from freshwater and marine animals of N and/or P excretion rates. These observations represent 491 species, including most aquatic phyla. Coverage varies greatly among phyla and other taxonomic levels. The dataset includes information on animal body size, ambient temperature, taxonomic affiliations, and animal body N:P. This data set was used to test predictions of MTE and ES, as described in Vanni and McIntyre (2016; Ecology; DOI : 10.1002/ecy.1582

A global database of nitrogen and phosphorous excretion rates of aquatic animals

Animals can be important in modulating ecosystem-level nutrient cycling, although their importance varies greatly among species and ecosystems. Nutrient cycling rates of individual animals represent valuable data for testing the predictions of important frameworks such as the Metabolic Theory of Ecology (MTE) and ecological stoichiometry (ES). They also represent an important set of functional traits that may reflect both environmental and phylogenetic influences. Over the past two decades, studies of animal-mediated nutrient cycling have increased dramatically, especially in aquatic ecosystems. Here we present a global compilation of aquatic animal nutrient excretion rates. The dataset includes 10,534 observations from freshwater and marine animals of N and/or P excretion rates. These observations represent 491 species, including most aquatic phyla. Coverage varies greatly among phyla and other taxonomic levels. The dataset includes information on animal body size, ambient temperature, taxonomic affiliations, and animal body N:P. This data set was used to test predictions of MTE and ES, as described in Vanni and McIntyre (2016; Ecology DOI: 10.1002/ecy.1582). © 2017 Ecological Society of Americ