AD8361(中文版功能說明)

1、ad8361是用于低頻到2.5ghz的功率檢測器一：features(特性)：calibrated rms response（標(biāo)準(zhǔn)化的均方根響應(yīng)）excellent temperature stability（極好的溫度穩(wěn)定性）up to 30db input range at 2.5ghz（高達(dá)30db的輸入范圍在2.5ghz）700 mv rms,10dbm re 50 maximum input（0.25db linear response up to 2.5ghz（正負(fù)0.25db線性響應(yīng)）single supply operation: 2.7v to 5.5v(單工作電壓)low

2、power:3.3mw at 3v supply(低功耗)rapid power-down to less than 1ua(快速掉電到小于1ua)二：applications(應(yīng)用)1：measurement of cdma,w-cdma,qam,（cdma,w-cdma,qam,的測量）2：other complex modulation waveforms（其他復(fù)雜的波形調(diào)整）3：rf transmitter or receiver power measurement（射頻發(fā)射器或接收器的功率測量）三：product description(產(chǎn)品描述）the ad8361 is a me

3、an-responding power detector for use in high-frequency receiver and transmitter signal chains, up to 2.5ghz.（ad8361是一個平均響應(yīng)的功率檢測器當(dāng)被用于高頻接收器和發(fā)射器信號鏈，高達(dá)2.5ghz）it is very easy to apply. it requires only a single supply between 2.7 v and 5.5 v, power supply decoupling capacitor（去耦電容） and an input coupling

4、capacitor（耦合電容） in most applications. the output is a linear-responding dc voltage with a conversion gain（轉(zhuǎn)換增益） of 7.5 v/vrms.（他應(yīng)用方便，僅要求一個2.7v到5.5v的單電源，電源的去耦電容和輸入的耦合電容，在大多數(shù)應(yīng)用中，輸出是一個線性響應(yīng)直流電壓，轉(zhuǎn)換增益為：7.5v/vrms.）an external lter capacitor（濾波電容） can be added to increase the averaging time constant.（一個外接的濾

5、波電容能有利于提高平均時間常數(shù)）cw(continuous wave ,連續(xù)波）the ad8361 is intended for true power measurement of simple and complex waveforms.（ad8361被用于簡單的和復(fù)雜的波形的功率測量）the device is particularly useful for measuring high crest-factor(high peak-to-rms ratio) signals,such as cdma,w-cdma.（這個器件特別的被用于高波峰因數(shù)crest-factor信號的測量，例

6、如cdma,w-cdma）四：工作模式the ad8361 has three operating modes to accommodate(適應(yīng)）a variety of analog-to-digital requirement:（有3中工作模式以適應(yīng)各種各樣的模數(shù)轉(zhuǎn)換的需求）1. ground referenced mode, in witch the origin is 0;（接地參考模式下，無信號時輸出為0v）2. internal referenced mode,in witch the origin is 0.35v（在內(nèi)部參考模式下，無信號時輸出為0.35v）3. supply

7、 referenced mode,in witch the origin is vs/7.5v（在電源參考模式下，無信號時輸出為vs/7.5v）參考模式irefsrefoutputno signaloutput接地參考模式接電源接地07.5vin內(nèi)部參考模式懸空接地0.35v7.5vin+0.35v電源參考模式接電源接電源vs/7.57.5vin+vs/7.5由上圖figure 35可知，rfin的偏壓（bias voltage）范圍為0v到0.8v，輸出電壓范圍為0v到4.9v。五：輸入耦合，匹配，駐波比in all modes,the device is powered by a sing

8、le supply of between 2.7v and 5.5v.the vpos pin is decoupled using 100pf and 0.01uf capacitors.(在所有的模式下，此期間被提供1個2.7v-5.5v的單電源，vpos腳被退耦用100pf和0.01uf的電容。）the quiescent current of 1.1ma in operating mode can be reduced to 1ua by pulling the pwdn pin up to vpos.（在工作模式下，1.1ma的靜態(tài)電流能夠被降低到1ua，通過pwdn腳接電源腳vpo

9、s）a 75歐external shunt resistance combines with the ac-coupled input to give an overall broadband input impedance near 50歐。（1個75歐的外接分流電阻與ac耦合輸入結(jié)合，來提供1個約為50歐的全部寬帶輸入阻抗）。note that the coupling capacitor must be placed between the input and the shunt impedance.（請注意，耦合電容必須安置在輸入腳和分流阻抗之間）the input coupling

10、capacitor combines with the internal input resistance to give a high-pass corner frequency given by the equation.（輸入耦合電容與內(nèi)部輸入電阻相結(jié)合，由這個方程來提供1個高通角頻率。）a number of options exist for input matching.（輸入匹配存在多種選擇）for operation at multiple frequency,a 75 shunt to ground,as shown in figure 39a,will provide th

11、e best overall match.（在多頻操作下，ruth39a所示，1個75歐分流到地的電阻rsh，將提供最好的整體匹配）for use at a single frequency, a resistive or a reactive match can be used.（單一頻率使用時，一個電阻或1個失配都可以使用）by plotting the input impedance on a smith chart（測繪出輸入阻抗在史密斯原圖上）the best value for a resistive match can be calculated.（最佳匹配電阻值可以被計算出）t

12、he vswr can be held below 1.5 at frequencies up to 1ghz,even as the input impedance varies from part to part.at very high frequencies(1.9ghz to 2.5ghz),a shunt resistor will not be sufficient to reduce the vswr below 1.5.（在非常搞的頻率1.8ghz到2.5ghz，1個分流電阻將不足以降低駐波比到1.5下）where vswr is critical,remove shunt

13、component and insert an inductor in series with the coupling capacitor as shown in figure 39b。（在駐波比是關(guān)鍵的情況下，移除分流電阻rsh，并插入1個電感l(wèi)m和耦合電容串聯(lián)cc，如圖39b所示）table ii gives recommended shunt resistor values for various frequencies and series inductor values for high frequencies.(表2給出建議的分流電阻值在多種頻率下,和串聯(lián)電感值在高頻下)the

14、coupling capacitor,cc, essentially acts as an ac-short and plays no intentional part in the matching.(耦合電容cc本質(zhì)上作為隔直通交用，在匹配中不是策劃的部分）六：pin function descriptions(管教功能描述）1. vpos:supply voltage pin,operational range is 2.7v-5.5v;(電源腳，工作電壓范圍為2.7v-5.5v）2. iref :output reference control pin, when this pin i

15、s left open,internal referenced mode is enabled.otherwise this pin should be tied to vpos,dont ground this pin.（輸出參考控制腳，當(dāng)這個腳懸空時，工作模式為內(nèi)部參考模式，其他兩種模式下，此腳應(yīng)接電源，不能接地）3. rfin: signal input pin,must be driven from an ac-coupled source,the low frequency real input impedance is 225歐。（信號輸入腳，此腳必須被交流耦合源（此腳要串聯(lián)耦合電

16、容）驅(qū)動，低頻實際輸入阻抗為225歐。）4. pwdn: power-down pin,for the device to operate as a detector it needs a logical low input(less than 100mv).when a logical high(greater than vs-0.5v) is applied,the device is turned off and the supply current goes to nearly 0,(休眠控制腳，此期間作為檢測器工作是，此腳需要一個邏輯低電平輸入（小于100mv），當(dāng)一個邏輯高電平被提供時，此期間將關(guān)掉，并且電源電流變?yōu)?）此腳一般情況是接地。5. comm；device ground pin,(電源地）6. fltr:by placing capacitor between this pin and vpos,the corner frequency（角頻率）of the modulation filter(調(diào)制濾波器） is lowered,(在此腳和電源腳之間加電容，調(diào)制濾波器的角頻率被降低）7. vrms:output pin,near rial to rial voltage output with limited current drive ca