11 2014 档案
摘要：http://www.planetanalog.com/author.asp?section_id=3041&doc_id=563055Jonathan Harris, Product Applications Engineer, Analog Devices, 6/2/2014As I thoug...
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摘要：It's a Buck; It's a Boost, No! It's a Switcher!Sanjaya Maniktala, National Semiconductor Corp., Santa Clara, CAWe like to give everything a name or la...
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摘要：集成型5A 40V 宽输入范围升压/单端初级电感转换器(SEPIC) / 反激式(Flyback) 直流到直流稳压器 (Rev. B)描述TPS55340 是一款单片非同步开关稳压器，此稳压器带有集成的 5A，40V 电源开关。此器件可在几种标准开关稳压器拓扑结构中进行配置，这些拓扑结构包括升压、S...
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摘要：http://news.cnblogs.com/n/509750/（果壳翻译学习组/译）量子力学中最著名的那个思想实验的要旨就是，量子世界完全不同于我们所熟悉的世界。奥地利物理学家埃尔温·薛定谔（Erwin Schrödinger）让我们想象一只猫放在一个箱子里。这只猫的命运和量子世界紧密相连，因为...
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摘要：LTC3803 - 采用 ThinSOT 封装的恒定频率、电流模式、反激式 DC/DC 控制器特点VIN和 VOUT仅受限于外部元件可调斜率补偿内部软起动200kHz 恒定频率操作±1.5% 基准准确度旨在实现卓越的电压和负载瞬态响应的电流模式操作无最小负载要求低静态电流：240μA扁平 (高度仅 ...
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摘要：如何选择正确值的上拉电阻和下拉电阻？上拉电阻和下拉电阻是如何确定？还是在选择此类电阻的时候，有个特定的范围？对上拉电阻和下拉电阻的选择应结合开关管特性和下级电路的输入特性进行设定，主要需要考虑以下几个因素：1． 驱动能力与功耗的平衡。以上拉电阻为例，一般地说，上拉电阻越小，驱动能力越强，但功耗越大，...
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摘要：用四节 5 号电池供电的手持式设备，想要同时作出电池充电电路，且保证电源的输出稳定的 5V，该怎么实现呢？首先，我们要知道是否要用 4 节干电池来给别的电池充电？如是，给什么类型电池充电？充电器的要求是什么？至于 5V 输出，输出电流是多少？视乎输出功率及效率的要求，很多不同的方案都可用。最重要的是...
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摘要：升/降压转换器 (Buck-boost)当输入电压是变动的，有时比输出电压高、有时却比较低时(例如放电中的电池)，升/降压转换器 (Buck-boost)是最佳的电源解决方案。升/降压转换器 (Buck-boost) 内部的四组 MOSFET 开关依据输入电压和输出电压间的差异，自动切换为降压模式 ...
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摘要：升压转换器 (Boost)需要将输入电压转换为较高的输出电压时，升压转换器 (Boost)是唯一的选择。升压转换器透过内部 MOSFET 对电压充电来达成升压输出的目的，而当 MOSFET 关闭时，透过负载整流使该电感放电。电感充电及放电间的转换过程，会反转经过该电感的电压方向，进而逐步将电压拉抬得...
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摘要：降压转换器 (Buck)切换式降压转换器 (Buck)能提供高效率、高度弹性、高压降比、高负载能力的降压转换。多数降压转换器 (Buck) 包含上桥 MOSFET 和同步整流 MOSFET，根据占空比切换电路开关来产生稳定的平均输出电压。其切换波形再透过外部 LC 滤波器过滤。因为 MOSFET 是...
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摘要：线性稳压器 (LDO)当输出电压低于输入电压时，必须从负载电源和压降比来考虑要采用线性稳压器 (LDO) 或降压转换器 (Buck)低压降线性稳压器(LDO) 适合用在需求低噪讯、低电流和低压降比的应用中。LDO 透过线性的方式控制被动组件的导通来调节输出电压。线性稳压可提供准确而无噪讯的输出电压，...
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摘要：下表是一般情况下，挑选 LDO 或 DC/DC 切换式转换器的基本通则。首先，要先判定输入和输出之间的电压差 (VIN-VOUT)。其次，还得考虑特定的应用需求，例如效率要求、散热限制、噪讯承受力、系统复杂性、成本等多种条件，才能决定最合适的电源方案为何。下表是如何从线性稳压器 (LDO)、降压转换...
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摘要：AC/DC 反激控制器 (Flyback Controller)用于将交流电转换为稳定、隔离的直流电以供给应用系统。交流电首先需整流为高压的直流电。返驰控制器的工作原理类似一个升-降压控制器 (Buck-boost) ，但采用分离的电感来形成变压器。返驰控制器控制高压开关 MOSFET Q1的导通与...
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摘要：single ended primary inductor converter单端初级电感转换器SEPIC(single ended primary inductor converter) 是一种允许输出电压大于、小于或者等于输入电压的DCDC变换器。输出电压由主控开关(三极管或MOS管)的占空比控...
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摘要：引言当今的许多电子设备都需要一个负输出或正输出转换器，有时则是两者均需要。另外，它们还必需采用各种电源运作，包括 USB、墙上适配器、碱性电池和锂电池等。为了从可变输入电压产生不同极性的输出，电源设计师常常采用多种稳压器 IC，因而导致库存元器件品种的增加。LT®3759 可在 1.6V 至 42V...
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摘要：http://cds.linear.com/docs/cn/design-note/DN317%20sim_chs.pdfhttp://cds.linear.com/docs/en/datasheet/1961fa.pdf
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摘要：The AD736 true-rms-to-dcconverter is useful for many applications that require precise calculation of the rms value of a waveform. This converter can ...
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摘要：With an n- and p-channel MOSFET, you can easily implement a single-pole double-throw (SPDT) switch to isolate part of a circuit and power it from a se...
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摘要：Many designs need deep buffering but don't require ultrahigh-memory bandwidth. Examples include image and audio processing, as well as some deep-FIFO ...
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摘要：Figure 1shows an example of on/off circuitry commonly used in battery-operated devices. The p-channel MOSFET, Q1, serves as a power switch. When you p...
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摘要：Figure 1shows a simple, stand-alone overvoltage detector. The intent of the circuit is to monitor a voltage, VMONITOR, and set the output, VOUT, high ...
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摘要：
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摘要：A standard technique for generating analog voltages using µCs is to use a PWM output and filter the signal with a simple RC filter (Figure 1). The vol...
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摘要：Short-circuit protection is an obvious requirement for a power supply, especially when its load connects to a cable that's subject to damage. Many mod...
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摘要：The circuit inFigure 1is a good choice if you need a power supply with high efficiency and you don't want to use expensive dc/dc-converter ICs. The he...
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摘要：The circuit inFigure 1produces a single debounced pulse each time you press S1. Moreover, the circuit uses only logic power from the remote pull-up re...
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摘要：Many applications require current sources rather than voltage sources. When you need a high-current source, using a linear regulator is inadvisable, b...
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摘要：Linear Technology's recently introduced LTC4300 chip buffers I2C clock and data lines to and from a hot-swappable card. This task is difficult because...
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摘要：The achievable accuracy for systems with multiple ADCs depends directly on the reference voltages applied to the ADCs. Medical-ultrasound-imaging syst...
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摘要：The easy way to clamp a signal to a given value is to use two zener diodes, connected back-to-back. This method has several disadvantages. The accurac...
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摘要：ECL circuits typically have relatively small logic spans of approximately 800 mV. Because of the small span, to drive TTL circuits from ECL levels nor...
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摘要：A number of circuits, such as level detectors and AM demodulators, benefit from a rectifier with a low offset voltage. Silicon diodes have an offset o...
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摘要：The circuit inFigure 1uses a minimal number of external parts to raise the maximum output current of a 0.5A buck switching-regulator IC to more than 6...
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摘要：Boost converters, like other switchers, have traditionally received their control signals from a dedicated circuit. However, a recent trend is to inte...
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摘要：The schematic inFigure 1shows a way to increase the power available from a current-limited 5V supply by adding power from a –5V supply. The dc/dc conv...
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摘要：In certain dc/dc-converter applications, on-chip, cycle-by-cycle current limit may be insufficient protection to prevent a failure during a short circ...
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摘要：AC signals can emanate from many sources, and many of these sources are incompatible with the most popular interface voltages, such as TTL. A temptati...
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摘要：This Design Idea explores level-shifting an I2C bus from 5V/ground (positive domain) to ground/–5V (negative domain). In multisupply systems, you some...
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摘要：Low-ripple-voltage positive-to-negative dc/dc converters find use in many of today's high- frequency and noise-sensitive disk drives, battery-powered ...
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摘要：The popular USB interface can charge a portable device while transferring data. But for high-capacity batteries, the 500-mA output current of USB host...
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摘要：Many embedded-microcontroller applications require generation of analog signals. An integrated or stand-alone DAC fills the role. However, you can oft...
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摘要：The SEPIC (single-ended, primary-inductance-converter) topology is generally a good choice for voltage regulators that must produce an on output volta...
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摘要：LT1961 升压型稳压器造就了兼具升压和降压能力的扁平状SEPICTransformerless dc/dc converter produces bipolar outputsWell-regulated, dual-polarity power supplies find wide use i...
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摘要：Dual-polarity supply provides ±12V from one ICVC (Pin 1): Error Amplifier Output Pin. Tie external compensationnetwork to this pin or use the internal...
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摘要：You can easily use a PC's printer port for serial-EEPROM programming. You can use a device-programmer circuit used to program the MicroWire serial EE-...
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摘要：Added components improve switching-regulator stability
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摘要：Targeting use in portable-system applications that require raising a battery's voltage to a higher level, IC boost regulators often include output tra...
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摘要：Synchronous buck regulators offer high efficiency and are popular in applications in which available input voltages are 12V or less. However, as input...
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摘要：For containing large amounts ofbulk capacitance, controllinginrush currents poses problems.Thesimplest approach involves placing aninrush-limiting res...
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摘要：The circuit inFigure 1delivers programming voltages to an EEPROM under the control of an external DAC (not shown).You can replace the DAC with a poten...
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摘要：The classic LM317 adjustable-output linear voltage regulator offers a relatively high, if package-dependent, current-handling capability. In addition,...
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摘要：Buck regulators find wide application as step-down regulators for converting large positive input voltages into a smaller positive output voltages.Fig...
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摘要：You would normally use a series linear regulator or a dc/dc converter to obtain 3V dc from a higher supply. However, when breadboarding a concept, you...
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摘要：In new mixed-voltage systems, it is often necessary to level-shift a control signal from a high level to a low level. An open-drain device, such as th...
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摘要：http://www.edn.com/design/analog/4329365/Combine-two-8-bit-outputs-to-make-one-16-bit-DAC
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摘要：This Design Idea stems from the limited availability of IC voltage regulators that can meet key USB-power specs, coupled with the need for turn-on seq...
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摘要：Voltage-regulator design for high output currents can be a critical and difficult task. Although voltage regulators with 1A maximum output current are...
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摘要：Adding a current-mirror circuit to a typical boost circuit allows you to select the amount of boost voltageand to ensure a constant difference between...
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摘要：The step-up switching-converter circuit inFigure 1presents a familiar problem: If you shut down boost converter IC1by pulling itsinput low, external i...
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摘要：In multiple-output power supplies in which a single supply powers circuitry of vastly different current draws, two perplexing steps are sensing the cu...
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摘要：Most isolated, offline SMPSs (switched-mode power supplies), including flyback, forward, and resonant, must operate at input voltages of 90 to 260V rm...
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摘要：Batteries are the typical power sources for portable-system applications, and it is not unusual these days to find microcontroller-based portable syst...
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摘要：An inexpensive way to implement high-resolution digital-to-analog conversion is to combine microcontroller-PWM (pulse-width-modulated) outputs with pr...
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摘要：Digital potentiometers, such asAnalog Devices’ AD5160, make excellent digitally controlled voltage dividers in applications in which 8-bit resolution ...
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摘要：Engineering labs are usually equipped with various power supplies, voltmeters, function generators, and oscilloscopes. One piece of equipment missing ...
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摘要：You can easily add margining capability—that is, the ability to digitally adjust the output voltage—to a dc/dc converter by making a single connection...
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摘要：Most engineers know that they can use an inexpensive, three-terminal adjustable regulator, such asFairchild Semiconductor’s LM317, as an adjustable re...
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摘要：Using a PN-junction diode for temperature measurement usually depends on its 2‑mV/K temperature coefficient. Conventionally, you must amplify and digi...
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摘要：Driving LEDs at a regulated current from low supply voltages can be difficult because minimal overhead voltage is available for control circuits. A cu...
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摘要：Sensors automate most of the processes in industry. Most of these sensors, such as those for ammonia gas, temperature, and the like, are resistive dev...
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摘要：Emerging digital ICs for power control lack basic features, such as the built-in gate drive and current limiting, that you would normally find in anal...
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摘要：The most common switching-power topology is a buck converter, which efficiently transforms high voltages to low voltages.Figure 1shows a typical buck ...
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摘要：A previous Design Idea describes a programmable current source that used a three-terminalNational SemiconductorLM317 adjustable regulator (Reference 1...
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摘要：Industrial controls make heavy use of 4- to 20-mA current loops to transmit process measurements because current loops retain information in the prese...
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摘要：A variable resistor that integrates a programmable, temperature-indexed look-up table can compensate for the temperature drift of a voltage regulator....
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摘要：The USB (Universal Serial Bus) specification requires a connected USB device to present a load to the host or hub of no greater than 10 µF in parallel...
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摘要：Low-cost, 8-bit, single-chip microcontrollers are stingy when it comes to on-chip PWM (pulse-width-modulation) resources. The use of a PWM resource of...
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摘要：Many electronic devices require user input for setting the application properties. Typical input devices include pushbuttons, potentiometers, and touc...
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摘要：Few microcontrollers include a DAC. Although you can easily find an inexpensive DAC to control from your microcontroller, you can use unused periphera...
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摘要：Must tri-state outputs and use an external resistor to pull up to 5VTo drive 5V CMOS-level inputs, a pull-up resistor must be applied to the 5V Virtex...
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摘要：基本的晶体管开关电路饱和开关的问题点：OFF延时时间如图1所示，使场效应晶体管开关动作时，加给晶体管的基极电流IB：IB=IC/hFE，决定的值大的电流。这是由于晶体管的集电极一发射极饱和电压VCE(set)减小，使晶体管的ON时的电力损耗降低的缘故。这样，晶体管饱和动作时，如图2所示，基极电流IB...
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摘要：+VO的输出电压峰值可达2倍V_IN，-VO的输出电压可达-V_IN。需要注意的是，3路的峰值电路不能超过1.5A，同时两路附加电源的输出功率和必须小于V_IN·I·(1-D)，其中I为主输出的电流，D为占空比。在此两路输出电流不大的情况下，此电路可以很好地降低实现升压和负压电源的成本。
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摘要：When we engineers look at the complexity of system design these days, we are challenged with cramming more functions into a smaller space, while consu...
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摘要：http://davidkessner.wordpress.com/2011/05/01/adc-in-an-fpga/Geek Alert! What follows is very technical. It involves ADC’s, FPGA’s, and sophisticated e...
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摘要：http://www.design-reuse.com/articles/14886/fully-digital-implemented-delta-sigma-analog-to-digital-converter.htmlby Dr. MichaelGude &GerrietMuellerCol...
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摘要：http://www.eetimes.com/author.asp?section_id=36&doc_id=1320289Seeing the new ADC IP being bandied about by FPGA vendors got William Murray wondering w...
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摘要：http://letsmakerobots.com/node/13843Reading A Sensor With HigherAccuracy – RC Timing MethodRC Timing Method:Simple RC step responseVc(t) = VDD * (1 - ...
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摘要：http://www.21ic.com/app/eda/200905/42832.htmhttp://www.eefocus.com/article/09-10/84673s.html摘 要 简要分析sigma—deIta(∑一△)架构模数转换器(ADC)原理，提出一种基于FPGA内部LVDS(Lo...
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摘要：http://electronics.stackexchange.com/questions/6676/which-sipo-chip-is-better-74hc4094-or-74hc595-or-something-elseI want to drive lots of LEDs in a s...
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摘要：http://www.edaboard.com/thread227388.htmlHi, i have designed a 48 pin universal programmer but need help finishing it off, is anyone up for the challa...
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摘要：DLL Injection and Hookinghttp://securityxploded.com/dll-injection-and-hooking.phpThree Ways to Inject Your Code into Another Processhttp://www.codepro...
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摘要：http://www.jx19.com/xxzl/Delphi/2010/04/17/ShiZhanDELPHI_YuanChengXianChengChaRu_DLLZhuRu/远程注入DLL方法有很多种，也是很多木马病毒所使用的隐藏进程的方法，因为通过程序加载的DLL在进程管理器是没有显示的．这...
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摘要：线程的远程注入要实现线程的远程注入必须使用Windows提供的CreateRemoteThread函数来创建一个远程线程该函数的原型如下：HANDLE CreateRemoteThread( HANDLE hProcess, LPSECURITY_ATTRIBUTES lpThreadAttribu...
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摘要：http://hi.baidu.com/43755979/blog/item/3ac19711ea01bdc4a6ef3f6a.html要对一个任意进程（包括系统安全进程和服务进程）进行指定了写相关的访问权的 OpenProcess操作，只要当前进程具有SeDeDebug权限就可以了。要是一个用户是...
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摘要：http://huaidan.org/archives/838.html原版地址：http://www.codeproject.com/threads/winspy.asp?df=100&forumid=16291&select=1025152&msg=1025152pdf格式下载：http://n...
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摘要：http://www.45it.com/windowszh/201212/33946.htmhttp://www.hx95.cn/Article/OS/201212/65095.html我们知道将动态连接库注入到其他进程中有很多种方法。最常见的方法是使用钩子函数(Hook)，但是这种方法主要有两个缺...
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摘要：https://code.google.com/p/busdog/busdog is a filter driver for MS Windows (XP and above) to sniff USB traffic.https://busdog.googlecode.com/files/busd...
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摘要：Version 3.6 - Last revised August 5, 2009The Eclipse platform is highly configurable. Configuration input takes the form of command line arguments and...
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摘要：http://www.21jn.net/html/72/n-272.htmlWindows下JAVA用到的环境变量主要有3个，JAVA_HOME、CLASSPATH、PATH。下面逐个分析。JAVA_HOME指向的是JDK的安装路径，如C:\jdk1.5.0_06，在这路径下你应该能够找到bin、l...
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摘要：Linux/drivers/usb/serial/ftdi_sio.h 1 /* 2 * Driver definitions for the FTDI USB Single Port Serial Converter - 3 * known as FTDI_SIO (Serial Inp...
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摘要：JSONJSON(JavaScript Object Notation) 是一种轻量级的数据交换格式。它基于JavaScript（Standard ECMA-262 3rd Edition - December 1999）的一个子集。 JSON采用完全独立于语言的文本格式，但是也使用了类似于C语言家...
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摘要：http://zh.wikipedia.org/wiki/VCardvCard是电子名片的文件格式标准。它一般附加在电子邮件之后，但也可以用于其它场合（如在互联网上相互交换）。vCard可包含的信息有：姓名、地址资讯、电话号码、URL，logo，相片等。历史vCard（或称做Versitcard）最...
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摘要：http://www.tuicool.com/articles/7FZVZna第一次看到这个错误还以为是修改文件导致的，但是觉得又不大像，因为在Win7底下是完全正常的。搜索了一下才发现是由于插件导致的：NOTE3:You get a “Fatal error before kernel init”...
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摘要：http://wiki.eclipse.org/Eclipse.iniOverviewEclipse startup is controlled by the options in$ECLIPSE_HOME/eclipse.ini. If$ECLIPSE_HOMEis not defined, th...
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摘要：eclipse.ini 文件使用说明The -vm option and its value (the path) must be on separate lines.The value must be the full absolute or relative path to the Java e...
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