Abstract: Transimpedance amplifiers (TIAs) are widely used to translate the current output of sensors like photodiode-to-voltagesignals, since several circuits and instruments can only accept voltage input. An operational amplifier with a feedback resistor fromoutput to the inverting input is the most straightforward implementation of such a TIA. However, even this simple TIA circuit requirescareful trade-offs among noise gain, offset voltage, bandwidth, and stability. Clearly stability in a TIA is essential for good, reliableperformance. This application note explains the empirical calculations for assessing stability and then shows how to fine-tune theselection of the feedback phase-compensation capacitor.
Calculation of the Differential Impedance of Tracks on FR4 substrates
There is a discrepancy between calculated and measured values of impedance for differential transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. calculations, using Boundary Element field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.
Abstract: A resistive feedback network is often used to set the output voltage of a power supply. A mechanical potentiometer (pot)conveniently solves the problem of adjusting a power supply. For easier automatic calibration, a mechanical pot can be replaced witha digital pot. This application note presents a calibration solution that uses a digital pot, because digipots are smaller, do not movewith age or vibration, and can be recalibrated remotely. This proposed solution reduces the susceptibility of the system to thetolerance of the digital pot's end-to-end resistance, making the solution optimal fordesigners. This application note also explainssome of the equations required to calculate the resistor chain values and to use a digital pot in this way. A spreadsheet withstandard reisistor values is available for easy calculations.
PCA9511, PCA9512, PCA9513, PCA9514, PCA9515, PCA9516, PCA9518,P82B96, P82B715Abstract - Philips Semiconductors family of Repeaters, Hubs and Expanders are detailed in this application notethat discusses device operation, maximum cable length and frequency calculations and typical applications.
The main objective of this book is to present all the relevant informationrequired for RF and micro-wave power amplifier design includingwell-known and novel theoretical approaches and practical design techniquesas well as to suggest optimum design approaches effectively combininganalytical calculations and computer-aided design. This bookcan also be very useful for lecturing to promote the analytical way ofthinking with practical verification by making a bridge between theoryand practice of RF and microwave engineering. As it often happens, anew result is the well-forgotten old one. Therefore, the demonstrationof not only new results based on new technologies or circuit schematicsis given, but some sufficiently old ideas or approaches are also introduced,that could be very useful in modern practice or could contributeto appearance of new ideas or schematic techniques.
Calculation of the Differential Impedance of Tracks on FR4 substrates
There is a discrepancy between calculated and measured values of impedance for differential transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. calculations, using Boundary Element field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.
The goal of this project is to explore the idea of point-based
radiosity, which is a shooting radiosity technique suggested by Mark
Harris at UNC. The primary idea is that features available in
graphics hardware can be utilized to perform radiosity calculations.
Facilities such as flat shading, diffuse lighting, projective
textures, and mipmapping can be used to replace traditional numerical
solutions for radiosity.
* CONSTRAINTS
* This module does not handle data which is considered out of range by the
* application(i.e. fixed constants which represent error condition)
*
* Maximum weight value must be limited to 128 to prevent an overflow
* condition during the calculation.
*
* The internal data type must be large enough to handle the calculations.
* The maximum possible internal value
* = Max Input Value * (weight - 1) + Max Input Value
* If a maximum weight of 128 is used, the internal data type should be 2
* times the size of the input data type.
Uniform random number generators
by Agner Fog, 2001 - 2007
randomc.zip contains a C++ class library of uniform random number generators of good quality.
The random number generators found in standard libraries are often of a poor quality, insufficient for large Monte Carlo calculations. This C++ implementation provides random number generators of a much better quality: Better randomness, higher resolution, and longer cycle lengths.
The same random number generators are available as libraries coded in assembly language for higher speed. These libraries can be linked into projects coded in other programming languages under Windows, Linux, BSD, etc. The library files are available in the archive asmlib.zip.
Non-uniform random number generators are provided in stocc.zip.
