This application note features 8-, 10-, and 12-bit dataacquisition components in various circuit configurations.The circuits include battery monitoring, temperature sensing,isolated serial interfaces, and microprocessor andmicrocontroller serial and parallel interfaces. Also includedare voltage reference circuits (Application Note 42contains more voltage reference circuits).
標(biāo)簽: 數(shù)據(jù)采集 電路分析
上傳時(shí)間: 2014-01-15
上傳用戶:zq70996813
開關(guān)在電路中起接通信號(hào)或斷開信號(hào)的作用。最常見的可控開關(guān)是繼電器,當(dāng)給驅(qū)動(dòng)繼電器的驅(qū)動(dòng)電路加高電平或低電平時(shí),繼電器就吸合或釋放,其觸點(diǎn)接通或斷開電路。CMOS模擬開關(guān)是一種可控開關(guān),它不象繼電器那樣可以用在大電流、高電壓場合,只適于處理幅度不超過其工作電壓、電流較小的模擬或數(shù)字信號(hào)。 一、常用CMOS模擬開關(guān)引腳功能和工作原理 1.四雙向模擬開關(guān)CD4066 CD4066 的引腳功能如圖1所示。每個(gè)封裝內(nèi)部有4個(gè)獨(dú)立的模擬開關(guān),每個(gè)模擬開關(guān)有輸入、輸出、控制三個(gè)端子,其中輸入端和輸出端可互換。當(dāng)控制端加高電平時(shí),開關(guān)導(dǎo)通;當(dāng)控制端加低電平時(shí)開關(guān)截止。模擬開關(guān)導(dǎo)通時(shí),導(dǎo)通電阻為幾十歐姆;模擬開關(guān)截止時(shí),呈現(xiàn)很高的阻抗,可以看成為開路。模擬開關(guān)可傳輸數(shù)字信號(hào)和模擬信號(hào),可傳輸?shù)哪M信號(hào)的上限頻率為40MHz。各開關(guān)間的串?dāng)_很小,典型值為-50dB。
標(biāo)簽: CMOS 模擬開關(guān) 工作原理
上傳時(shí)間: 2013-10-27
上傳用戶:bibirnovis
Finite state machines are widely used in digital circuit designs. Generally, when designing a state machine using an HDL, the synthesis tools will optimize away all states that cannot be reached and generate a highly optimized circuit. Sometimes, however, the optimization is not acceptable. For example, if the circuit powers up in an invalid state, or the circuit is in an extreme working environment and a glitch sends it into an undesired state, the circuit may never get back to its normal operating condition.
標(biāo)簽: Creating Machines Mentor State
上傳時(shí)間: 2013-10-08
上傳用戶:wangzhen1990
減小電磁干擾的印刷電路板設(shè)計(jì)原則 內(nèi) 容 摘要……1 1 背景…1 1.1 射頻源.1 1.2 表面貼裝芯片和通孔元器件.1 1.3 靜態(tài)引腳活動(dòng)引腳和輸入.1 1.4 基本回路……..2 1.4.1 回路和偶極子的對稱性3 1.5 差模和共模…..3 2 電路板布局…4 2.1 電源和地…….4 2.1.1 感抗……4 2.1.2 兩層板和四層板4 2.1.3 單層板和二層板設(shè)計(jì)中的微處理器地.4 2.1.4 信號(hào)返回地……5 2.1.5 模擬數(shù)字和高壓…….5 2.1.6 模擬電源引腳和模擬參考電壓.5 2.1.7 四層板中電源平面因該怎么做和不應(yīng)該怎么做…….5 2.2 兩層板中的電源分配.6 2.2.1 單點(diǎn)和多點(diǎn)分配.6 2.2.2 星型分配6 2.2.3 格柵化地.7 2.2.4 旁路和鐵氧體磁珠……9 2.2.5 使噪聲靠近磁珠……..10 2.3 電路板分區(qū)…11 2.4 信號(hào)線……...12 2.4.1 容性和感性串?dāng)_……...12 2.4.2 天線因素和長度規(guī)則...12 2.4.3 串聯(lián)終端傳輸線…..13 2.4.4 輸入阻抗匹配...13 2.5 電纜和接插件……...13 2.5.1 差模和共模噪聲……...14 2.5.2 串?dāng)_模型……..14 2.5.3 返回線路數(shù)目..14 2.5.4 對板外信號(hào)I/O的建議14 2.5.5 隔離噪聲和靜電放電ESD .14 2.6 其他布局問題……...14 2.6.1 汽車和用戶應(yīng)用帶鍵盤和顯示器的前端面板印刷電路板...15 2.6.2 易感性布局…...15 3 屏蔽..16 3.1 工作原理…...16 3.2 屏蔽接地…...16 3.3 電纜和屏蔽旁路………………..16 4 總結(jié)…………………………………………17 5 參考文獻(xiàn)………………………17
標(biāo)簽: 印刷電路板 設(shè)計(jì)原則
上傳時(shí)間: 2013-10-24
上傳用戶:18165383642
目錄 第一章 傳輸線理論 一 傳輸線原理 二 微帶傳輸線 三 微帶傳輸線之不連續(xù)分析 第二章 被動(dòng)組件之電感設(shè)計(jì)與分析 一 電感原理 二 電感結(jié)構(gòu)與分析 三 電感設(shè)計(jì)與模擬 電感分析與量測
標(biāo)簽: 傳輸線
上傳時(shí)間: 2013-12-12
上傳用戶:浩子GG
特點(diǎn)(FEATURES) 精確度0.1%滿刻度 (Accuracy 0.1%F.S.) 可作各式數(shù)學(xué)演算式功能如:A+B/A-B/AxB/A/B/A&B(Hi or Lo)/|A| (Math functioA+B/A-B/AxB/A/B/A&B(Hi&Lo)/|A|/etc.....) 16 BIT 類比輸出功能(16 bit DAC isolating analog output function) 輸入/輸出1/輸出2絕緣耐壓2仟伏特/1分鐘(Dielectric strength 2KVac/1min. (input/output1/output2/power)) 寬范圍交直流兩用電源設(shè)計(jì)(Wide input range for auxiliary power) 尺寸小,穩(wěn)定性高(Dimension small and High stability)
標(biāo)簽: 微電腦 數(shù)學(xué)演算 輸出 隔離傳送器
上傳時(shí)間: 2013-11-24
上傳用戶:541657925
Linear Technology’s DC/DC step-down μModule®regulators are complete switchmode power supplies in asurface-mount package. They include the DC/DC controller,inductor, power switches and supporting circuitry.These highly integrated regulators also provide an easysolution for applications that require negative outputvoltages. In other words, these products can operate asinverting buck-boost regulators. As a result, the lowestpotential in the circuit is not the standard 0V, but –VOUT,which must be tied to the μModule regulator’s GND. Allsignals are now referred to –VOUT.
標(biāo)簽: Module 如何制作 降壓穩(wěn)壓器 輸入輸出
上傳時(shí)間: 2013-10-22
上傳用戶:ztj182002
#include<iom16v.h> #include<macros.h> #define uint unsigned int #define uchar unsigned char uint a,b,c,d=0; void delay(c) { for for(a=0;a<c;a++) for(b=0;b<12;b++); }; uchar tab[]={ 0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,
標(biāo)簽: AVR 單片機(jī) 數(shù)碼管
上傳時(shí)間: 2013-10-21
上傳用戶:13788529953
利用Atmel公司的ATmega168微處理器,采用A/D轉(zhuǎn)換方式來實(shí)現(xiàn)按摩椅控制器的鍵盤接口,通過在硬件電路中巧妙地選擇電阻,在軟件設(shè)計(jì)中采用數(shù)字濾波、二分法和區(qū)間鑒定等方法,靈敏可靠地實(shí)現(xiàn)了按摩椅中30個(gè)按鍵的處理。給出了硬件電路設(shè)計(jì)和軟件設(shè)計(jì)思想以及部分匯編代碼。 Abstract: This paper chooses A/D conversion method to realize the keyboard interface of the controller by using ATmega168 microchip from Atmel Company.It accomplishes 30-key dealing sensitively and reliably in massage chair through skillfully selecting resistors in hardware circuit and using digital filter,dichotomy and area-judging method in software design.The hardware design circuit, software design idea and partly assembles code are presented mainly.
上傳時(shí)間: 2014-01-10
上傳用戶:咔樂塢
引言 在數(shù)字信息傳輸中,基帶數(shù)字信號(hào)通常要經(jīng)過調(diào)制器調(diào)制,將頻率搬移到適合信息傳輸?shù)念l段上。2FSK就是用數(shù)字信號(hào)去調(diào)制載波的頻率(移頻鍵控),由于它具有方法簡單、易于實(shí)現(xiàn)、抗噪聲和抗衰落性能較強(qiáng)等優(yōu)點(diǎn),因此在現(xiàn)代數(shù)字通信系統(tǒng)的低、中速數(shù)據(jù)傳輸中得到了廣泛應(yīng)用。 直接數(shù)字頻率合成技術(shù)(DDS)將先進(jìn)的數(shù)字處理技術(shù)與方法引入信號(hào)合成領(lǐng)域。DDS器件采用高速數(shù)字電路和高速D/A轉(zhuǎn)換技術(shù),具備頻率轉(zhuǎn)換時(shí)間短、頻率分辨率高、頻率穩(wěn)定度高、輸出信號(hào)頻率和相位可快速程控切換等優(yōu)點(diǎn),可以實(shí)現(xiàn)對信號(hào)的全數(shù)字式調(diào)制。
標(biāo)簽: C8051F060 9833 FSK AD
上傳時(shí)間: 2014-12-27
上傳用戶:1427796291
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