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ANALOG INPUT BANDWIDTH is a measure of the frequencyat which the reconstructed output fundamental drops3 dB below its low frequency value for a full scale input. Thetest is performed with fIN equal to 100 kHz plus integer multiplesof fCLK. The input frequency at which the output is −3dB relative to the low frequency input signal is the full powerbandwidth.APERTURE JITTER is the variation in aperture delay fromsample to sample. Aperture jitter shows up as input noise.APERTURE DELAY See Sampling Delay.BOTTOM OFFSET is the difference between the input voltagethat just causes the output code to transition to the firstcode and the negative reference voltage. Bottom Offset isdefined as EOB = VZT–VRB, where VZT is the first code transitioninput voltage and VRB is the lower reference voltage.Note that this is different from the normal Zero Scale Error.CONVERSION LATENCY See PIPELINE DELAY.CONVERSION TIME is the time required for a completemeasurement by an analog-to-digital converter. Since theConversion Time does not include acquisition time, multiplexerset up time, or other elements of a complete conversioncycle, the conversion time may be less than theThroughput Time.DC COMMON-MODE ERROR is a specification which appliesto ADCs with differential inputs. It is the change in theoutput code that occurs when the analog voltages on the twoinputs are changed by an equal amount. It is usually expressed in LSBs.
標(biāo)簽：
Converter
Defi
ADC
轉(zhuǎn)換器
上傳時(shí)間：
2013-11-12
上傳用戶：pans0ul
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Abstract: Investment in smart meters and smart grid end equipment continues to grow worldwide as countriestry to make their electric delivery systems more efficient. However, as critical as the electric deliveryinfrastructure is, it is normally not secured and thus subject to attack. This article describes the concept oflife-cycle security—the idea that embedded equipment in the smart grid must have security designed into theentire life of the product, even back to the contract manufacturer. We also talk about how life-cycle securityapplies to embedded equipment in the smart grid. Potential threats are discussed, as are potential solutionsto mitigate the risks posed by those threats.
標(biāo)簽：
智能電表
智能電網(wǎng)
上傳時(shí)間：
2014-12-24
上傳用戶：熊少鋒
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This document presents design techniques and reference circuits that power Virtex™-4 FXRocketIO™ multi-gigabit transceivers (MGTs) operating at data rates below 3.125 Gb/s.When using multiple transceivers, it is sometimes preferred to power them from a switchingpower supply. However, switching power supplies generate noise that affects transceiver
標(biāo)簽：
RocketIO
Virtex
XAPP
946
上傳時(shí)間：
2013-11-18
上傳用戶：huang111
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高的工作電壓高達(dá)100V N雙N溝道MOSFET同步驅(qū)動 The D810DCDC is a synchronous step-down switching regulator controller that can directly step-down voltages from up to 100V, making it ideal for telecom and automotive applications. The D810DCDC uses a constant on-time valley current control architecture to deliver very low duty cycles with accurate cycle-by-cycle current limit, without requiring a sense resistor. A precise internal reference provides 0.5% DC accuracy. A high bandwidth (25MHz) error amplifi er provides very fast line and load transient response. Large 1Ω gate drivers allow the D810DCDC to drive multiple MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in VIN and can also be synchronized to an external clock for switching-noise sensitive applications. Integrated bias control generates gate drive power from the input supply during start-up and when an output shortcircuit occurs, with the addition of a small external SOT23 MOSFET. When in regulation, power is derived from the output for higher effi ciency.
標(biāo)簽：
DCDC
100
12V
BOM
上傳時(shí)間：
2013-10-24
上傳用戶：wd450412225
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Although recent popular attention is focused on LithiumIon batteries, one must not forget that other batterychemistries, such as Nickel Cadmium (NiCd) and NickelMetal Hydride (NiMH) have advantages in rechargeablepower systems. Nickel-based batteries are robust, capableof high discharge rates, have good cycle life, do notrequire special protection circuitry and are less expensivethan Li-Ion. Among the two, NiMH batteries are rapidlyreplacing NiCd because of their higher capacity (40% to50% more) and the environmental concerns of the toxiccadmium contained in NiCd batteries.
標(biāo)簽：
NiMH
NiCd
獨(dú)立
電池充電
上傳時(shí)間：
2013-11-04
上傳用戶：qq10538412
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For a variety of reasons, it is desirable to charge batteriesas rapidly as possible. At the same time, overchargingmust be limited to prolong battery life. Such limitation ofovercharging depends on factors such as the choice ofcharge termination technique and the use of multi-rate/multi-stage charging schemes. The majority of batterycharger ICs available today lock the user into one fixedcharging regimen, with at best a limited number ofcustomization options to suit a variety of application needsor battery types. The LTC®1325 addresses these shortcomingsby providing the user with all the functionalblocks needed to implement a simple but highly flexiblebattery charger (see Figure 1) which not only addressesthe issue of charging batteries but also those of batteryconditioning and capacity monitoring.
標(biāo)簽：
1325
LTC
IC的
電池管理
上傳時(shí)間：
2013-10-19
上傳用戶：royzhangsz
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IC 特色 :
˙ 半諧振模式之 ZVS零電壓切換 , 能有效降低切換損失 , 提高效率 , 并具展頻功能 , 改善EMI .
˙ 輕 / 重載的 Duty Factor 皆在 CCM 與 DCM 邊緣 , 是最能發(fā)揮次級 "同步整流" 效率的一種工作模式 .
˙ 空載時(shí)進(jìn)入 Cycle Skipping ( Typical 0.3W ) , 有效達(dá)成環(huán)保規(guī)範(fàn) .
˙ 內(nèi)建 "LEB前緣遮沒" 功能 , 避免電流迴授失真 .
˙ 能隨輸入電壓變化 , 自動補(bǔ)償 OPP過功率保護(hù)點(diǎn) .
˙ 精密的 OVP 過壓保護(hù)點(diǎn)可自行設(shè)定 .
˙ 完整的保護(hù)功能 : OVP過壓保護(hù) , OCP過流保護(hù) , OPP過載保護(hù) ,
SWP線圈短路保護(hù) , SCP輸出短路保護(hù) , OTP過溫度保護(hù) .
標(biāo)簽：
飛利浦
綠色電源
集成電路
選型
上傳時(shí)間：
2014-12-24
上傳用戶：回電話#
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詳細(xì)介紹工控軟件組態(tài)王與單片機(jī)多機(jī)串口通訊的設(shè)計(jì)原理。分析組態(tài)王提供的直接與單片機(jī)串口通信方法的優(yōu)點(diǎn)，給出系統(tǒng)基于RS-485總線傳輸?shù)慕涌陔娐吩韴D。根據(jù)組態(tài)王提供的通訊協(xié)議和單片機(jī)多機(jī)串口通訊的原理，給出程序設(shè)計(jì)流程與思路。
Abstract:
In this paper，the design principle of communication between multi-SCM and KingView by serial ports is described in detail.We analysis the advantage of method supplied by KingView,by which KingView can communicate with serial ports of SCM directly，and provide the system’s interface circuit based on the RS-485transmission line.We provide flow diagram of programming and thinking on the basis of communication protocol supplied by KingView and principle of communication among multi-SCM through serial ports.
標(biāo)簽：
工控軟件
單片機(jī)
串口通訊
多機(jī)
上傳時(shí)間：
2013-12-19
上傳用戶：tecman
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實(shí)時(shí)時(shí)鐘是微機(jī)保護(hù)裝置的重要部件，在討論P(yáng)CF8583結(jié)構(gòu)與功能的基礎(chǔ)上，提出采用dsPIC33F系列微處理器與串行I2C時(shí)鐘PCF8583的接口設(shè)計(jì)方案，給出了相應(yīng)的接口電路與軟件流程。該設(shè)計(jì)方案結(jié)構(gòu)簡單，可靠性高，開發(fā)周期短，具有一定的實(shí)用與參考價(jià)值。所設(shè)計(jì)的微機(jī)保護(hù)裝置已投入現(xiàn)場運(yùn)行，效果良好。
Abstract:
Real-time clock chip is an important part in microcomputer protection device.Based on discussing the structure and function of PCF8583，a new interface scheme which uses dsPIC33F microprocessor and serial clock chip（I2C）PCF8583is proposed.The method of the circuit design and the main software flow are introduced in this paper.The scheme has simple structure，higher reliability and shorter exploitation cycle，so has definite practicality or reference value.The microcomputer protection device has been put into operation with better effects.
標(biāo)簽：
8583
PCF
串行時(shí)鐘
中的應(yīng)用
上傳時(shí)間：
2013-11-18
上傳用戶：Thuan
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以89S52單片機(jī)和EP1C6Q240C8型FPGA為控制核心的多功能計(jì)數(shù)器，是由峰值檢波、A/D轉(zhuǎn)換、程控放大、比較整形、移相網(wǎng)絡(luò)部分組成,可實(shí)現(xiàn)測量正弦信號的頻率、周期和相位差的功能。多功能計(jì)數(shù)器采用等精度的測量方法，可實(shí)現(xiàn)頻率為1Hz～10MHz、幅度為0.01～5Vrms的正弦信號的精確測頻，以及頻率為10Hz～100kHz、幅度為0.5～5Vrms的正弦信號精確測相。液晶顯示器能夠?qū)崟r(shí)顯示當(dāng)前信號的頻率、周期和相位差。該多功能計(jì)數(shù)器精度高，界面友好，實(shí)用性強(qiáng)。
Abstract:
A multi-function counter，which uses89S52MCU and EP1C6Q240C8FPGA as a control core，consists of peak detector，A/D conversion，program-controlled amplification，compared shaping and phase-shifting network part.The counter measures the frequency，period and phase of sinusoidal signal.With the equal precision method,the multi-function counter achieves the precise frequency measurement of the sinusoidal signal which its frequency is from1Hz to10MHz，its amplitude is from0.01Vrms to5Vrms，as well as the accurate phase measurement of the sinusoidal signal which its frequency is from10Hz to100kHz，its amplitude is from0.5Vrms to5Vrms.The LCD monitor real-time displays the frequency，period and phase difference of current signal.The multi-function counter features high precision，friendly interface，and strong practical.
標(biāo)簽：
FPGA
單片機(jī)
多功能
計(jì)數(shù)器
上傳時(shí)間：
2013-11-15
上傳用戶：gy592333
