<bdo id="syioo"></bdo>
pcb布線技巧內(nèi)含6張pdf，講述數(shù)字模擬混合布線技巧-pcb routing technique includes six pdf
標(biāo)簽： pcb
上傳時(shí)間： 2013-07-19
上傳用戶：ruan2570406
微弱信號(hào)檢測(cè)裝置 四川理工學(xué)院 劉鵬飛、梁天德、曾學(xué)明 摘要： 本設(shè)計(jì)以TI的Launch Pad為核心板，采用鎖相放大技術(shù)設(shè)計(jì)并制作了一套微弱信號(hào)檢測(cè)裝置，用以檢測(cè)在強(qiáng)噪聲背景下已知頻率微弱正弦波信號(hào)的幅度值，并在液晶屏上數(shù)字顯示出所測(cè)信號(hào)相應(yīng)的幅度值。實(shí)驗(yàn)結(jié)果顯示其抗干擾能力強(qiáng)，測(cè)量精度高。 關(guān)鍵詞：強(qiáng)噪聲；微弱信號(hào)；鎖相放大；Launch Pad Abstract: This design is based on the Launch Pad of TI core board, using a lock-in amplifier technique designed and produced a weak signal detection device, to measure the known frequency sine wave signal amplitude values of the weak in the high noise background, and shows the measured signal amplitude of the corresponding value in the liquid crystal screen. Test results showed that it has high accuracy and strong anti-jamming capability. Keywords: weak signal detection; lock-in-amplifier; Launch Pad 1、引言 隨著現(xiàn)代科學(xué)技術(shù)的發(fā)展，在科研與生產(chǎn)過(guò)程中人們?cè)絹?lái)越需要從復(fù)雜高強(qiáng)度的噪聲中檢測(cè)出有用的微弱信號(hào)，因此對(duì)微弱信號(hào)的檢測(cè)成為當(dāng)前科研的熱點(diǎn)。微弱信號(hào)并不意味著信號(hào)幅度小，而是指被噪聲淹沒(méi)的信號(hào)，“微弱”也僅是相對(duì)于噪聲而言的。只有在有效抑制噪聲的條件下有選擇的放大微弱信號(hào)的幅度，才能提取出有用信號(hào)。微弱信號(hào)檢測(cè)技術(shù)的應(yīng)用相當(dāng)廣泛，在生物醫(yī)學(xué)、光學(xué)、電學(xué)、材料科學(xué)等相關(guān)領(lǐng)域顯得愈發(fā)重要。 2、方案論證 針對(duì)微弱信號(hào)的檢測(cè)的方法有很多，比如濾波法、取樣積分器、鎖相放大器等。下面就針對(duì)這幾種方法做一簡(jiǎn)要說(shuō)明。 方案一：濾波法。 在大部分的檢測(cè)儀器中都要用到濾波方法對(duì)模擬信號(hào)進(jìn)行一定的處理，例如隔離直流分量，改善信號(hào)波形，防止離散化時(shí)的波形混疊，克服噪聲的不利影響，提高信噪比等。常用的噪聲濾波器有：帶通、帶阻、高通、低通等。但是濾波方法檢測(cè)信號(hào)不能用于信號(hào)頻譜與噪聲頻譜重疊的情況，有其局限性。雖然可以對(duì)濾波器的通頻帶進(jìn)行調(diào)節(jié)，但其噪聲抑制能力有限，同時(shí)其準(zhǔn)確性與穩(wěn)定性將大打折扣。
標(biāo)簽： 2012 TI 電子設(shè)計(jì)大賽 微弱信號(hào)
上傳時(shí)間： 2013-11-04
上傳用戶：lty6899826
The LTC®1966 is a true RMS-to-DC converter that uses aDS computational technique to make it dramatically simplerto use, significantly more accurate, lower in powerconsumption and more flexible than conventional logantilogRMS-to-DC converters. The LTC1966 RMS-to-DCconverter has an input signal range from 5mVRMS to1.5VRMS (a 50dB dynamic range with a single 5V supplyrail) and a 3dB bandwidth of 800kHz with signal crestfactors up to four.
標(biāo)簽： 真有效值 轉(zhuǎn)換器 自動(dòng)調(diào)節(jié)
上傳時(shí)間： 2013-10-12
上傳用戶：qilin
A tutorial on SAR type A/D converters, this note contains detailed information on several 12-bit circuits. Comparator, clocking, and preamplifier designs are discussed. A final circuit gives a 12-bit conversion in 1.8µs. Appended sections explain the basic SAR technique and explore D/A considerations.
標(biāo)簽： 逐次逼近 AD轉(zhuǎn)換器
上傳時(shí)間： 2014-01-21
上傳用戶：釣鰲牧馬
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.
上傳時(shí)間： 2013-10-19
上傳用戶：royzhangsz
該系統(tǒng)由單片機(jī)89S52控制模塊，程控寬帶放大模塊，整形模塊，F(xiàn)PGA內(nèi)頻率、相位差測(cè)量模塊等構(gòu)成，采用等精度測(cè)頻法測(cè)出頻率和周期，可測(cè)量有效值為0.01～5V，頻率范圍1Hz～20MHz信號(hào)的頻率、周期信號(hào)，精度高達(dá)10-6。采用計(jì)數(shù)法測(cè)量相位差，該系統(tǒng)可測(cè)量有效值0.5～5V，頻率10Hz～100kHz信號(hào)的相位差，精度為1°。系統(tǒng)功能由按鍵控制，測(cè)量結(jié)果實(shí)時(shí)顯示，人機(jī)界面友好。 Abstract: The system consists of the following functional blocks:89S52microcontroller controlling module,programmable amplifier module,comparator module,frequency and phase difference testing module in the FPGA.The system use the equal accuracy frequency-examining technique it measures frequency and circle of signal which its ranges is from1Hz to20MHz and the amplitude of which its range is from0.01Vrms to5Vrms,precision is up to10-6.Using of count method,the system detects the phase difference of signal,the amplitude of whic its range is from0.5Vrms to5Vrms and the frequency of which its ranges is from10Hz to100kHz,precision is up to1°,The system functions is controlled by certain keys,measurement results are displayed in real-time and it is friendly interface.
標(biāo)簽： 89S52 單片機(jī) 多功能 計(jì)數(shù)器
上傳時(shí)間： 2013-11-04
上傳用戶：CHINA526
介紹了MPC555與CS8900A擴(kuò)展以太網(wǎng)的硬件設(shè)計(jì)圖。以NUCLUES PLUS操作系統(tǒng)為基礎(chǔ)，介紹了網(wǎng)卡軟件驅(qū)動(dòng)程序的編制，給出了以太網(wǎng)協(xié)議包嵌入NUCLEUS PLUS操作系統(tǒng)的實(shí)現(xiàn)方法。 Abstract: The Ethernet extension hardware design of MPC555 and CS8900A are introduced,and the software driven program based on NUCLEUS PLUS operation system and the technique that Ethernet protocol embedded in NUCLEUS PLUS real operation system are discussed.
上傳時(shí)間： 2013-10-23
上傳用戶：xiehao13
為了提高環(huán)境參數(shù)采集的自動(dòng)化水平，提升效率，設(shè)計(jì)了無(wú)線傳感器系統(tǒng)。本系統(tǒng)運(yùn)用了傳感器技術(shù)、通信技術(shù)和單片機(jī)技術(shù)，實(shí)現(xiàn)了對(duì)環(huán)境溫度、濕度、光照度以及可燃性氣體濃度等參數(shù)的檢測(cè)。它能夠?qū)崟r(shí)地與上位機(jī)進(jìn)行無(wú)線通信，滿足對(duì)環(huán)境參數(shù)實(shí)時(shí)監(jiān)測(cè)的要求。 Abstract: In order to increase the degree of automation and improve the efficiency of the environment monitoring parameters，the wireless sensor system was developed.Combining with the technique of sensor,automatic monitoring，communication and single-chip microcomputer，it realized real-time monitoring environment parameters,such as temperature，humidity，illumination，concentration of com- bustible gas and so on.At the same time it can communicate with upper personal computers，satisfy the desire of real-time monitoring.
上傳時(shí)間： 2013-11-22
上傳用戶：longlong12345678
Luminary Micro provides an analog-to-digital converter (ADC) module on some members of theStellaris microcontroller family. The hardware resolution of the ADC is 10 bits; however, due to noiseand other accuracy-diminishing factors, the true accuracy is less than 10 bits. This application noteprovides a software-based oversampling technique, resulting in an improved Effective Number OfBits (ENOB) in the conversion result. This document describes methods of oversampling an inputsignal, and the impact on precision and overall system performance.
標(biāo)簽： Oversampling techniques ADC fo
上傳時(shí)間： 2013-12-17
上傳用戶：zhyiroy
The 87C576 includes two separate methods of programming theEPROM array, the traditional modified Quick-Pulse method, and anew On-Board Programming technique (OBP).Quick Pulse programming is a method using a number of devicepins in parallel (see Figure 1) and is the traditional way in which87C51 family members have been programmed. The Quick-Pulsemethod supports the following programming functions:– program USER EPROM– verify USER EPROM– program KEY EPROM– program security bits– verify security bits– read signature bytesThe Quick-Pulse method is quite easily suited to standardprogramming equipment as evidenced by the numerous vendors of87C51 compatible programmers on the market today. Onedisadvantage is that this method is not well suited to programming inthe embedded application because of the large number of signallines that must be isolated from the application. In addition, parallelsignals from a programmer would need to be cabled to theapplication’s circuit board, or the application circuit board wouldneed to have logic built-in to perform the programming functions.These requirements have generally made in-circuit programmingusing the modified Quick Pulse method impractical in almost all87C51 family applications.
上傳時(shí)間： 2013-10-21
上傳用戶：xiaozhiqban
蟲蟲下載站版權(quán)所有 京ICP備2021023401號(hào)-1
