07 2013 档案
摘要：http://www.altera.com/literature/hb/max2/max2_mii51009.pdfThe open-drain pin never drives high, only low or tri-state. When the open-drain pinis active, it drives low. When the open-drain pin is inactive, the pin is tri-stated and the trace pulls up to 5.0 V by the external resistor. The purpose of
阅读全文
摘要：Connect a ARM Microcontroller to a FPGA using its Extended Memory Interface (EMI)http://elinux.org/Connect_a_ARM_Microcontroller_to_a_FPGA_using_its_Extended_Memory_Interface_(EMI)http://www.makestuff.eu/wordpress/software/fpgalink/http://www.techonlineindia.com/techonline/design_centers/170438/inte
阅读全文
摘要：http://www.ti.com/lit/ds/symlink/sn74lvc1g29.pdf
阅读全文
摘要：The SILICA Xynergy-M4 Board combines an ARM Cortex-M4 based STMicroelectronics STM32F417 controller with a Xilinx Spartan-6 low-cost FPGA (XC6SLX16) in one design.There are numerous development tools for either ARM Cortex-M microcontrollers or FPGA kits, but this is the first module in the market th
阅读全文
摘要：Key FeaturesHigh-performance FPGA configuration and PROM/CPLD programmingIncludes innovative FPGA-based acceleration firmware encapsulated in a small form factor pod attached to the cableSupports JTAG and Slave-Serial programming topologiesFirmware downloadable over cableEasy to useFully integrated
阅读全文
摘要：XPROG-m编程器是为取代较早版本的XPROG编程器而设计的。XPROG-m编程器硬件完全与XPROG编程器向上兼容，还具有其它许多功能。该XPROG - M支持摩托罗拉68HC05，68HC08，68HC11，68HC（S）12，HC912，MC9S12，MC9S12X，德州仪器TMS370，M...
阅读全文
摘要：http://bbs.ednchina.com/BLOG_ARTICLE_18577.HTM电感是储能元件，而磁珠是能量转换（消耗）器件。电感多用于电源滤波回路，侧重于抑止传导性干扰；磁珠多用于信号回路，主要用于EMI方面。磁珠用来吸收超高频信号，象一些RF电路，PLL，振荡电路，含超高频存储器电路（DDR,SDRAM,AMBUS等）都需要在电源输入部分加磁珠，而电感是一种储能元件，用在LC振荡电路、中低频的滤波电路等，其应用频率范围很少超过50MHz。1.片式电感：在电子设备的PCB板电路中会大量使用感性元件和EMI滤波器元件。这些元件包括片式电感和片式磁珠，以下就这两种器件的特点进行描述并
阅读全文
摘要：IC开短路测试(open_short_test),编程器测试接触不良、开短路用的该是这个原理http://kitebee.gnway.net/forum.php?mod=viewthread&tid=69654IC开短路测试(open_short_test)又叫continuity test 或contact test,它是一种非常快速发现芯片的各个引脚间的是否有短路，及在芯片封装时是否missing bond wires.通常都会被放测试程序的最前面.它还能发现测试时接触是否良好，探针卡或测试座是否有问题.开短路测试的测试原理比较简单，分open_short_to_VDD 测试和op
阅读全文
摘要：http://www.ideyi.org/article/11-05/2575971305526398.html?sort=2068_2073_2092_0MP1593制作的DC-DC稳压电源，这款DC-DC稳压电源的体积很小，但它能提供2A 甚至最高达3A 的输出电流，并且其性能指标非常好，下面就...
阅读全文
摘要：http://dangerousprototypes.com/docs/Bus_BlasterBus Blaster v2 is an experimental, high-speed JTAG debugger for ARM processors, FPGAs, CPLDs, flash, and more. Thanks to a reprogrammable buffer, a simple USB update makes Bus Blaster v2 compatible with many different JTAG debugger types in the most pop
阅读全文
摘要：http://www.dzsc.com/data/html/2008-12-23/75397.htmlJTAG测试信号由下面5个信号组成。 TRST：测试复位输入信号，测试接口初始化 TCK：测试时钟，在TCK时钟的同步作用下，通过TDI和TDO引脚串行移入／移出数据或指令；同时，也为TAP（测试访问端口）控制器的状态机提供时钟。 TMS：测试模式选择信号，控制测试接口状态机的操作。 TDI：测试数据输入线，其串行输入数据至边界扫描寄存器或指令寄存器（由TAP控制器的当前状态及己保存在指令寄存器中的指令来控制）。 TDO：测试数据输出线，把从边界扫描链采样的数据传输至串行测试电路中的...
阅读全文
摘要：http://www.amobbs.com/thread-3293203-1-1.html首先必须要了解电感的一些特性:电磁转换与磁储能.其它所有参数都是由这两个特性引出来的.电感回路通电瞬间断电瞬间相信有初中文化是坛友们都知道,一个电池对一个线圈通电,这是个电磁铁.不论你是否科盲,你一定会奇怪,这有什么值得分析的呢?有!我们要分析它通电和断电的瞬间发生了什么.线圈(以后叫作"电感"了)有一个特性---电磁转换,电可以变成磁,磁也可以变回电.当通电瞬间,电会变为磁并以磁的形式储存在电感内.而断电瞬磁会变成电,从电感中释放出来.现在我们看看下图,断电瞬间发生了什么:前面我说过
阅读全文
摘要：http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011794In many applications, a DC/DC Converter is used to produce...
阅读全文
摘要：http://analogtalk.com/?p=534http://analogtalk.com/?p=551Posted byAnalogAdvocateon April 09, 2010Design,GeneralIn today’s highly competitive electronics environment, designers are constantly looking for ways to reduce overall system costs. One of the most commonly asked questions that analog speciali
阅读全文
摘要：http://www.edn.com/design/analog/4337128/Make-a-DAC-with-a-microcontroller-s-PWM-timerMany embedded-microcontroller applications require generation of analog signals. An integrated or stand-alone DAC fills the role. However, you can often use PWM signals for generating the required analog signals. Y
阅读全文
摘要：http://pdfserv.maximintegrated.com/en/an/AN818.pdfhttp://www.maximintegrated.com/app-notes/index.mvp/id/818Digital Adjustment of DC-DC Converter Output Voltage in Portable ApplicationsAbstract:This tutorial discusses methods for digitally adjusting the output voltage of a DC-DC converter. The digita
阅读全文
摘要：随着FT232H USB2.0高速芯片的发布，英商飞特蒂亚公司(FTDI)进一步巩固了其在USB接口集成电路产品的地位。此款多功能的单通道USB转UART/FIFO接口设备可通过EEPROM配置为各种不同的串行或并行接口。与FTDI建设完备精良的USB设备驱动一起，这套方案使工程师可以轻松的将高速 USB连接引入新的和传统的外设设计中。另外，还有相关的UM232H评估模块帮助工程师快速建立设计样机，测试FT232H集成到新的系统设计的适用性。其高度集成的USB设备控制器包含USB， 串行和并行协议引擎，而不需要开发USB专用固件。设备支持3.3V的IO接口电平，允许5V输入，使之适用于连接各种
阅读全文
摘要：http://www.360doc.com/content/10/1102/16/2285160_66006645.shtmlRail to rail: 轨至轨，指器件的输入输出电压范围可以达到电源电压。 传统的模拟集成器件，如运放、A/D、D/A等，其模拟引脚的电压范围一般都达不到电源，以运放为例，电源为+/-15V的运放，为确保性能（首先是不损坏，其次是不反相，最后是足够的共模抑制比），输入范围一般不要超过+/-10V，常温下也不要超过+/-12V；输出范围，负载10kohm时一般只有+/-11V，小负载电阻(600ohm)时只能保证+/-10V。这对器件的应用带来很多不便。 rail..
阅读全文
摘要：TLC2262和TLC2264分别是TI公司双路和四路运算放大器，两种器件可以在单电源或双电源条件下供电，从而增强了动态的范围，可以达到轨对轨输出的性能。TLC226X系列与TLC225X的微功耗和TLC227X的交流性能方面兼容。它可在电池供电时消耗较低的电源电流，而仍然具有足够好的交流性能。噪声性能已经较以前生产的CMOS放大器具有显著的改进。每个放大器的电源电流只有200μA（典型值）。 TLC226x系列放大器，具有较高的输入阻抗和非常低的噪声，适合于高阻抗源的小信号调节，例如压电转感器。由于它的微功耗，使该器件非常适合于手持式监控和远距离感应的设备，另外增加了轨对轨输出的功能，致使该
阅读全文
摘要：LM358里面包括有两个高增益、独立的、内部频率补偿的双运放，适用于电压范围很宽的单电源，而且也适用于双电源工作方式，它的应用范围包括传感放大器、直流增益模块和其他所有可用单电源供电的使用运放的地方使用。LM358封装有塑封8引线双列直插式和贴片式两种。LM358的特点:. 内部频率补偿. 低输入偏流. 低输入失调电压和失调电流. 共模输入电压范围宽，包括接地. 差模输入电压范围宽，等于电源电压范围. 直流电压增益高(约100dB). 单位增益频带宽(约1MHz). 电源电压范围宽：单电源(3—30V)；. 双电源(±1.5 一±15V). 低功耗电流，适合于电池供电. 输
阅读全文
摘要：http://www.freelabs.com/~whitis/electronics/jtag/One of the big issues in making a JTAG pod is level translation. The state of level translation ICs leaves a LOT to be desired. You would think that there would be a lot of chips that you could apply 1.2-5V power and logic on port A and 1.2-5V (or 0V)
阅读全文
摘要：http://www.ethernut.de/en/hardware/turtelizer/Introducing Turtelizer 2OverviewTurtelizer 2 had been developed to provide JTAG Flash programming and debugging of ARM based boards via USB. Typical target boards areEthernut 3, theElektor Internet RadioorEthernut 5. However, as the hardware is based on
阅读全文
摘要：http://www.sigrok.org/wiki/Main_PageThesigrokproject aims at creating aportable, cross-platform, Free/Libre/Open-Source signal analysis software suitethat supports various device types, such aslogic analyzers,MSOs,oscilloscopes,multimeters,LCR meters,sound level meters,thermometers,hygrometers,anemo
阅读全文
摘要：http://www.willar.com/article/article_view.asp?id=463由DC-DC变换集成电路MC34063组成，34063 广泛应用于于DC-DC的电源转换电路中，本电路中的34063 接成升压电路形式，将5V电压升压到12-14.5V，得到编程所需的Vpp电压，R8、R9、R10组成电压取样电路。R11和Q1组成14V VPP电压切换电路Vout(输出电压)＝1.25V（１＋R2／R1）= 1.25V * ( (R1+R2) / R1 )R1=R10+R9=0.56K + 1.8K=2.36KR2=R8=20KVout = 1.25 * ( ( 2.36
阅读全文
摘要：Voltage Translation for Analog to Digital Interface ADChttp://openschemes.com/2010/03/23/zeroplus-logic-cube-review-and-teardown/LAP 16032 has 4.5MBIT...
阅读全文
摘要：http://www.faludi.com/bwsn/xbee-level-shifting/The XBee communication (RX/TX) pins definitelyoperateoff of a 5V signal with the Arduino. We’ve seen this a lot and done this a lot, and it certainly keeps things simple. That said, there’s nothing wrong with adding a level-shifting circuit to deliver 3
阅读全文
摘要：http://www.daycounter.com/Circuits/Level-Translators/Level-Translators.phtmlInterfacing 5V and 3V logic circuits is a common task. 3V logic is preferred to 5V logic because it consumes less power, so most microcontrollers and peripheral devices use the lower voltage logic. However, it is often the c
阅读全文
摘要：http://www.daycounter.com/Circuits/Short-Circuit-Protection/Short-Circuit-Protection.phtmlShort circuit protection is often a desirable feature to add to power amplifiers or power supplies, for both safety concerns and protection of circuitry.The circuit in the schematic below can be used to protect
阅读全文
摘要：http://electronicdesign.com/boards/non-inverting-level-shifter-requires-only-one-op-amp-one-supply-voltageWith portable battery-operated devices continuing to add functionality while shrinking in size, printed-circuit-board real estate becomes increasingly valuable. Single-supply circuitry can help
阅读全文
摘要：SN7407Convert TTL Voltage Levels to MOS LevelsHigh Sink-Current CapabilityInput Clamping Diodes Simplify SystemDesignOpen-Collector Driver for Indicator Lampsand RelaysInputs Fully Compatible With Most TTLCircuitsThese TTL hex buffers/drivers featurehigh-voltage open-collector outputs for interfacin
阅读全文
摘要：http://debugmo.de/2012/02/xvcd-the-xilinx-virtual-cable-daemon/I recently discovered an almost undocumented function in Xilinx ISE: the Xilinx virtual cable driver. It’s basically “a platform cable without a platform cable” (asmarcansaid so nicely) – it allows you use Impact (and Chipscope, and all
阅读全文
摘要：74HC125; 74HCT125Quad buffer/line driver; 3-stateThe 74HC125; 74HCT125 is a quad buffer/line driver with 3-state outputs controlled by the output enable inputs (nOE). A HIGH on nOE causes the outputs to assume a high impedance OFF-state. Inputs include clamp diodes. This enables the use of current l
阅读全文
摘要：74HC245/74HCT245The 74HC245; 74HCT245 is a high-speed Si-gate CMOS device and is pin compatiblewith Low-Power Schottky TTL (LSTTL).The 74HC245; 74HCT245 is an octal transceiver featuring non-inverting 3-state buscompatible outputs in both send and receive directions. The 74HC245; 74HCT245features an
阅读全文
摘要：http://www.amobbs.com/thread-5541344-1-2.html3.3V转5V：S3输入为0V时，NMOS管导通，S5＝S3＝0V；S3输入为3.3V时，NMOS管截止，S5上拉到5V；5V转3.3V：S5输入为0V时，NMOS管体二极管导通，S3＝0.7V，此时NMOS管导通，S3＝S5＝0V；S5输入为5V时，NMOS管截止，S3上拉到3.3V。NMOS管可以选用BSS138R2可以省略，NMOS管G极可以直接连接到3.3V电源，R2的作用是改善EMI性能。AN97055I2C电平转换
阅读全文
摘要：The TPS703xx family of devices is designed to provide a complete power management solution for TI DSP, processor power, ASIC, FPGA, and digital applications where dual output voltage regulators are required. Easy programmability of the sequencing function makes this family ideal for any TI DSP appli
阅读全文
摘要：In need of a programmer for PIC micro controllers I decided to build my own one. This programmer has been designated as "PIC JDM Prototype Programmer 1001" because it is very likely the 1001st PIC programmer :-)The programmer is basically operating as aJDM-programmer. Any programming softw
阅读全文
摘要：http://www.romanblack.com/smps/conv.htmWhat is it?This is a simple smps voltage converter,it makes an output voltage of +13.3v from a "standard" +5v supply as used with logic chips.I was contacted by hobby PIC programmer legendMyke Predkoabout designing a simple and cheap circuit to produc
阅读全文
摘要：http://www.nomad.ee/micros/mc34063a/index.shtmlThis is a simple-minded design tool that allows you to calculate component values MC34063A simple switcher chip. It displays the appropriate scematic diagram (step-up, step-down, or inverting) and checks for current and voltage limits. Feedback resistor
阅读全文
摘要：http://simon.derr.free.fr/site/spip/spip.php?article11This is a description of my very simplified home-made pickit2 clone.Basically I took the schematic in the User Guide and removed everything I could.What I removed:Leds (pretty useless)The eeproms (they are not even used by the firmware)The Vdd ci
阅读全文
摘要：http://uzzors2k.4hv.org/index.php?page=usbpicprogMy Tait Serial programmer works alright, but not every computer has a parallel port, and these days they're almost extinct. Most laptop don't even have a serial port! Thinking ahead a USB programmer seems like a smart investment. Fortunately s
阅读全文
摘要：BeeHive204 Very fast universal 4x 48-pindrive concurrent multiprogramming system with ISP capabilityBeeProg2 Very fast universal 48-pindrive Programmer with USB/LPT interface and ISP capabilityBeeProg2C Very fast universal 48-pindrive Programmer with USB interface and ISP capabilityBeeProg+ Universa
阅读全文
摘要：FeaturesSEEprogis universal programmer of all types of serial EEPROMs in 8-pin package. SEEprog enables programming EEPROMs with interface types IIC (24Cxx), Microwire (93Cxx) and SPI (25Cxx). Programmer supports programming LV EEPROMs (3.3V). The programmer is equipped by ZIF socket. The quality of
阅读全文
摘要：http://www.elnec.com/products/universal-programmers/beeprog2c/FPGA basedtotally reconfigurable 48powerful TTL pindriversprovide H/L/pull_up/pull_down and read capability for each pin of socket. Advanced pindrivers incorporatehigh-quality high-speedcircuitry to deliver signals without overshoot or gr
阅读全文
摘要：http://www.elnec.com/products/universal-programmers/smartprog2/40powerful TTL pindriversprovide H/L/pull_up/pull_down and read capability for each pin of socket. Advanced pindrivers incorporatehigh-quality high-speedcircuitry to deliver signals without overshoot or ground bounce for all supported de
阅读全文
摘要：http://www.circuitsathome.com/mcu/pic_vpp_limiterVOUT = 2.5V * ( 1 + 24/10 ) = 2.5 * 3.4 = 8.5VNewer PIC18s, such as my current favorite – PIC18F26K20, don’t like to be programmed with 12V. The datasheet maximum is 9V. Older Microchip programmers/debuggers, such as PicKit and ICD 2, do not support v
阅读全文
摘要：所有专为驱动白光LED而设计的IC都提供恒定电流夕其中尽大多数是基于电感或电荷泵的解决方案9这两种解决方案各有其优缺点。 电荷泵解决方案也称为开关电容器解决方案，利用分离电容器将电源从输进端传送至输出端，整个过程不需使用任何电感男所以是受欢迎的解决方案。电荷泵电源的体积很小，设计也很简单，选择组件时通常只需根据组件规格从中挑选适当的电容器。 电荷泵解决方案的主要缺点是它只能提供有限的输出电压范围，尽大多数电荷泵的转换比率最多只能达到输进电压的两倍，这表示输出电压不可能高于输进电压的两倍。因此，若想利用电荷泵驱动一个以上的白光LED，就必须采用并联驱动的方式。利用只能对输出电压进行稳压的电荷..
阅读全文
摘要：电感式升压转换器-AIC1896 AIC1896是一个脉冲宽度调变(Pulse-Width-Modulation;PWM)控制之升压型转换器,它可以提供一个定电流以驱动白光LED.(图五A)为升压转换器之等效电路图,当开关SW关闭时,电感L开始储存能量,此时负载端需求的能量是由输出电容所提供的,其等效电路如(图五B)所示,当开关SW打开时,原本储存在电感里的能量会连同输入电压的能量一同对输出电容充电,其等效电路如(图五C)所示图六)为AIC1896的内部构造示意图,PWM是其主要的控制模式.(图七A)描述PWM的控制方式,控制讯号VC是回馈电压(VFB)和参考电压(VREF)的比较结果,而VC
阅读全文
摘要：http://learn.adafruit.com/ice-tube-clock-kit/designTubes such as VFDs, Nixies, Decatrons, etc require high voltage to light the gas in the tube. For nixies, this iabout 170VDC. VFDs aren't as bad they only need about 30-50VDC. In order to reduce cost, we use the microconrtoller to make a boost c
阅读全文
摘要：http://blog.csdn.net/muge0913/article/details/6741064VCC,VDD,VEE,VSS,VPP表示的意义版本一：简单说来，可以这样理解：一、解释VCC：C=circuit 表示电路的意思, 即接入电路的电压；VDD：D=device 表示器件的意思, 即器件内部的工作电压；VSS：S=series 表示公共连接的意思，通常指电路公共接地端电压；VEE：负电压供电；VPP：编程/擦除电压。二、说明1、对于数字电路来说，VCC是电路的供电电压,VDD是芯片的工作电压（通常Vcc>Vdd），VSS是接地点。2、有些IC既有VDD引脚又有VCC引
阅读全文
摘要：征一个简单、可靠的电源过压保护电路http://www.amobbs.com/thread-5542005-1-1.html防过压：过压之后TVS导通，电流由正极流经自恢复保险再流经TVS到负极，自恢复保险升温，阻值变大，相当于断开，等电流撤去，自恢复保险温度下降，恢复导通防反接：反接时TVS直接导通，自恢复保险断开。如果觉得反应速度不够快的话，可以在二次侧并联一个比较大的电容，减慢电压上升速度。另外有个单一元件叫ZEN056V130A24LS，也是类似原理实现上述功能，datasheet如下TE PolyZen Devices 产品性能选择请见http://www.te.com.cn/cat
阅读全文
摘要：http://www.daxia.com/bibis/moredata30_1207792_29862.shtml图中DA和PWM任选其一, 当DA或PWM输出为0~1.25V时，输出在12.5V~5V之间可调。实际上，DA输出到1.875V时，输出可以调至1.25V将3K电阻改成7.68K，可以输出到1.25~30VMG_wmj,2576内部的参考电压1.23V跟外面的DA电压及Vout电压之间怎讲计算的？？另外，如果用DA的话，PWM及运放电路可以去掉吗？VOUT=((Vref/R1)-(Vda-Vref)/R2)*R3+Vref其中：R1为Vref端对地电阻；R2为DA输出串联电阻；R3
阅读全文
摘要：http://bbs.ednchina.com/BLOG_ARTICLE_3013105.HTMLM2677，是TI公司生产的高效率5A开关buck稳压器，由于它内部具备的lowON-registerDMOS功率开关，使得它能够驱动大电流负载。LM2677有+3.3V、+5V、+12V和AJUSTABLE四个版本，其中AJUSTABLE的输出范围是1.2V~37V，使用它可以做一个可调的恒压源。官方手册中给出的AJUSTABLE典型应用电路如下：在上图中，R1固定为1K，选择不同的R2值，就能得到不同的输出电压。VOUT=VREF*(R1+R2)/R1其中VREF=1.21V。如果需要得到14
阅读全文
摘要：http://blog.sina.com.cn/s/blog_4d144f6d0100clem.html电压跟随器的显著特点就是，输入阻抗高，而输出阻抗低，一般来说，输入阻抗要达到几兆欧姆是很容易做到的。输出阻抗低，通常可以到几欧姆，甚至更低。 在电路中，电压跟随器一般做缓冲级及隔离级。因为，电压放大器的输出阻抗一般比较高，通常在几千欧到几十千欧，如果后级的输入阻抗比较小，那么信号就会有相当的部分损耗在前级的输出电阻中。在这个时候，就需要电压跟随器来从中进行缓冲。起到承上启下的作用。应用电压跟随器的另外一个好处就是，提高了输入阻抗，这样，输入电容的容量可以大幅度减小，为应用高品质的电容提供了前
阅读全文
摘要：http://home.eeworld.com.cn/my/space-uid-425020-blogid-82340.html对应运放“虚短”、“虚断”和“虚地”三个概念，你知道多少？我们知道，由于运放的电压放大倍数很大，一般通用型运算放大器的开环电压放大倍数都在80 dB以上。而运放的输出电压是有限的，一般在 10V～14V。因此运放的差模输入电压不足1 mV，两输入端近似等电位，相当于 “短路”。开环电压放大倍数越大，两输入端的电位越接近相等。 ⑴虚短：集成运放的线性应用时，可近似地认为uN－uP＝0，uN＝uP时，即反相与同相输入端之间相当于短路，故称虚假短路，简称“虚短”。“虚短”.
阅读全文
摘要：http://www.freelabs.com/~whitis/electronics/jtag/Each JTAG enabled chip has a TAP controller with a state machine with 16 states.The state of the TMS pin at each TCK pulse dictates the transitions between states. These states help control whether you are shifting through the instruction register or
阅读全文
摘要：http://www.jtagtest.com/pinouts/PinoutsARM-20(used with almost all ARM-based microcontrollers)ARM-14(used as a lower pin-count version of ARM-20)MIPS EJTAGused with all MIPS microcontrollers (mostly embedded devices, can be found on many WiFi devices)Toshiba MIPSPhilips MIPSAVR JTAGCompatible with A
阅读全文
