While simplicity and high effi ciency (for cool running) areno longer optional features in isolated power supplies, itis traditionally diffi cult to achieve both. Achieving higheffi ciency often requires the use of advanced topologiesand home-brewed secondary synchronous rectifi cationschemes once reserved only for higher power applications.This only adds to the parts count and to the designcomplexity associated with the reference and optocouplercircuits typically used to maintain isolation. Fortunately, abreakthrough IC makes it possible to achieve both high efficiency and simplicity in a synchronous fl yback topology.The LT®3825 simplifi es and improves the performance oflow voltage, high current fl yback supplies by providingprecise synchronous rectifi er timing and eliminating theneed for optocoupler feedback while maintaining excellentregulation and superior loop response.
As the performance of many handheld devices approachesthat of laptop computers, design complexity also increases.Chief among them is thermal management—how doyou meet increasing performance demands while keepinga compact and small product cool in the user’s hand?For instance, as battery capacities inevitably increase,charge currents will also increase to maintain or improvetheir charge times. Traditional linear regulator-based batterychargers will not be able to meet the charge currentand effi ciency demands necessary to allow a product torun cool. What is needed is a switching-based chargerthat takes just about the same amount of space as a linearsolution—but without the heat.
An essential component of a noise-free audio device isa clean power supply, but few switching regulators canoperate at high efficiency while keeping the switchingfrequency out of the audio band. The LTC®3620 fills thisvoid. It is a high efficiency 15mA buck regulator with aprogrammable minimum switching frequency, making itpossible to virtually eliminate audible switching noise. Theinternal synchronous switches and low quiescent currentof this buck regulator provide the ability to maintain highefficiency, while its small footprint makes it ideal for tiny,low power audio applications.
Frequently, voltage reference stability and noise defi nemeasurement limits in instrumentation systems. In particular,reference noise often sets stable resolution limits.Reference voltages have decreased with the continuingdrop in system power supply voltages, making referencenoise increasingly important. The compressed signalprocessing range mandates a commensurate reductionin reference noise to maintain resolution. Noise ultimatelytranslates into quantization uncertainty in A to D converters,introducing jitter in applications such as scales, inertialnavigation systems, infrared thermography, DVMs andmedical imaging apparatus. A new low voltage reference,the LTC6655, has only 0.3ppm (775nV) noise at 2.5VOUT.Figure 1 lists salient specifi cations in tabular form. Accuracyand temperature coeffi cient are characteristic ofhigh grade, low voltage references. 0.1Hz to 10Hz noise,particularly noteworthy, is unequalled by any low voltageelectronic reference.
The Small C compiler translates a subset of the C language into
assembly language. It runs under PC/MS-DOS 2.1 and later. Small
C is compatible with the Microsoft and Small Mac assemblers.
Small C takes full advantage of the ability of these assemblers
to generate relocatable object code, to maintain libraries of
relocatable modules, and to link separately compiled program
modules. It supports a small memory model with one code and one
data/stack segment.
很好的linux內核調試軟件 兼轅馬，沒有密碼。
The ia64 and ix86 directories contain versions of kdb prior to v2.0
(kdb version v2.0, not the kernel version). Older versions of kdb had
complete patches for each architecture it supported, each patch included
all the common kdb code. This format was awkward to maintain and use
for multiple platforms.
Starting with kdb v2.0 there is a common patch against each kernel which
contains all the architecture independent code plus separate architecture
dependent patches. Either use an old style (v1.8 or v1.9) kdb patch or
use a new style (v2.0) common patch plus the corresponding architecture
dependent patch.
Purpose of this White Paper
This white paper describes a collection of standards, conventions, and guidelines for writing solid Java
code. They are based on sound, proven software engineering principles that lead to code that is easy to
understand, to maintain, and to enhance. Furthermore, by following these coding standards your
productivity as a Java developer should increase remarkably – Experience shows that by taking the time to
write high-quality code right from the start you will have a much easier time modifying it during the
development process. Finally, following a common set of coding standards leads to greater consistency,
making teams of developers significantly more productive.
The LabVIEW Development Guidelines describe many of the issues that
arise when developing large applications. The guidelines are based on the
advice of LabVIEW developers, and provide a basic survey of software
engineering techniques you might find useful when developing your
own projects.
There is also a discussion of style for creating VIs. Developers who have
used LabVIEW and are comfortable in the LabVIEW environment can use
the LabVIEW Development Guidelines to maintain a consistent and
effective style in their projects.
