浙江工業(yè)大學(xué)浙西分校信電系畢業(yè)設(shè)計(jì)（中英翻譯） 1 高精度正弦全自動(dòng)激勵(lì)信號源的設(shè)計(jì)與實(shí)現(xiàn) 摘要 ： 本文詳細(xì)地介紹了光敏 Z-元件、磁敏 Z-元件以及力敏 Z-元件的溫度補(bǔ)償原理與補(bǔ)償方法，供用戶利用光、磁、力敏 Z-元件進(jìn)行應(yīng)用開發(fā)時(shí)參考。 關(guān)鍵詞 ： Z-元件、敏感元件、溫度補(bǔ)償、光敏、磁敏、力敏 一、前言 半導(dǎo)體敏感元件對溫度都有一定的靈敏度。抑制溫度漂移是半導(dǎo)體敏感元件的常見問題， Z-元件也不例外。本文在前述文章的基礎(chǔ)上，詳細(xì)介紹 Z-元件的溫度補(bǔ)償原理與溫度補(bǔ)償方法，供光、磁、力敏 Z-元件應(yīng)用開發(fā)參考。 不同品種的 Z-元件均能以簡單的電路，分別對溫、光、磁 、力等外部激勵(lì)作用輸出模擬、開關(guān)或脈沖頻率信號 123，其中后兩種為數(shù)字信號，可構(gòu)成三端數(shù)字傳感器。這種三端數(shù)字傳感器不需放大和 A/D轉(zhuǎn)換就可與計(jì)算機(jī)直接通訊，直接用于多種物理參數(shù)的監(jiān)控、報(bào)警、檢測和計(jì)量，在數(shù)字信息時(shí)代具有廣泛的應(yīng)用前景，這是 Z-元件的技術(shù)優(yōu)勢。但由于 Z-元件是半導(dǎo)體敏感元件，對環(huán)境溫度影響必然也有一定的靈敏度，這將在有效輸出中因產(chǎn)生溫度漂移而嚴(yán)重影響檢測精度。因而，在高精度檢測計(jì)量中，除在生產(chǎn)工藝上、電路參數(shù)設(shè)計(jì)上應(yīng)盡可能降低光、磁、力敏 Z-元件的溫度靈敏度外，還必須研究 Z-元 件所特有的溫度補(bǔ)償技術(shù)。 Z-元件的工作原理本身很便于進(jìn)行溫度補(bǔ)償，補(bǔ)償方法也很多。同一品種的 Z-元件，因應(yīng)用電路組態(tài)不同，其補(bǔ)償原理與補(bǔ)償方法也不同，特就模擬、開關(guān)和脈沖頻率三種不同的輸出組態(tài)分別敘述如下。 二、模擬量輸出的溫度補(bǔ)償 對 Z-元件的模擬量輸出，溫度補(bǔ)償?shù)哪康氖强朔囟茸兓母蓴_，調(diào)整靜態(tài)工作點(diǎn)，使輸出電壓穩(wěn)定。 1應(yīng)用電路 Z-元件的模擬量輸出有正向應(yīng)用和反向應(yīng)用兩種方式。 2溫度補(bǔ)償原理和補(bǔ)償方法 溫度補(bǔ)償時(shí)應(yīng)以標(biāo)準(zhǔn)溫度 20 為溫度補(bǔ)償?shù)墓ぷ骰鶞?zhǔn)，其中令： TS：標(biāo)準(zhǔn)溫度 T：工作溫度 QS：標(biāo)準(zhǔn)溫度時(shí)的靜態(tài)工作點(diǎn) Q：工作溫度時(shí)的靜態(tài)工作點(diǎn) QS：溫度補(bǔ)償后的靜態(tài)工作點(diǎn) VOS：標(biāo)準(zhǔn)溫度時(shí)的輸出電壓 VO：工作溫度時(shí)的輸出電壓 浙江工業(yè)大學(xué)浙西分校信電系畢業(yè)設(shè)計(jì)（中英翻譯） 2 在標(biāo)準(zhǔn)溫度 TS 時(shí)，由電源電壓 E、負(fù)載電阻 RL 決定的負(fù)載線與 TS 時(shí)的 M1 區(qū)伏安特性（或反向特性）相交，確定靜態(tài)工作點(diǎn) QS，輸出電壓為 VOS。當(dāng)環(huán)境溫度從 TS 升高到 T 時(shí)，靜態(tài)工作點(diǎn) QS 沿負(fù)載線移動(dòng)到 Q，相應(yīng)使輸出電壓由 VOS 增加到 VO，且 VO VOS DVO，產(chǎn)生輸出漂移 DVO，。若采用補(bǔ)償措施在環(huán)境溫度 T 時(shí)使工作點(diǎn)由 Q 移動(dòng)到 QS，使 輸出電壓恢復(fù)為 VO，則可抑制輸出漂移，使 DVO 0，達(dá)到全補(bǔ)償。 (1)利用 NTC 熱敏電阻 基于溫度補(bǔ)償原理 ， 利用 NTC熱敏電阻 Rt取代負(fù)載電阻 RL， 標(biāo)準(zhǔn)溫度 TS 時(shí)負(fù)載電阻為 Rt，當(dāng)溫度升高到工作溫度 T時(shí)，使其阻值為 Rt，可使靜態(tài)工作點(diǎn)由 Q推移到 QS，由于 Rt.= Vth, but has the effective jump； But works as when ambient temperature change, then should not satisfy transformation condition VZ = Vth, does not send has the jump error. Former through reasonably chooses the static operating point to achieve, latter then should use the temperature compensation technology to perform to guarantee 2.temperature compensations principle Above already had analyzed, because Z- part Vth, Ith have the certain sensitivity to the temperature, therefore the Z- part switch quantity (light, magnetism and strength are sensitive) outputs can produce jumps in advance and the lag jump error. The user when designs the electric circuit, is the basis effective drive (light, magnetism and strength and so on) the size determined static operating point QS, the Z- part beginnings and ends voltage was VZS by now, and has the following relations: Vth -VZS=DV (1) When T ( ) elevates, because Vth reduces, DV reduces. When reduces to DV=0, when namely VZS =Vth, produced jumped in advance the error； Same principle, when T ( ) drops, because Vth increases, DV increases, when is big to the effective drive function, also does not have the jump, this has had the lag jump error. After we designated the load resistance RL value and supply voltage ES, static operating point QS determined. Therefore, the Z- part switching circuit designs the objective point should lie in DV the value. Also must guarantee Z- part when effective drive, can have the effective jump； But through temperature compensation can guarantee DV the initial design value along with the temperature change, then does not eliminate jumps in advance erroneous and the lag jump error. 3. temperature compensations method (1) load resistance determination Switch quantity output output low level VOL is not a straight line, its change rule as well as jump peak-to-peak value and M1 area characteristic and static operating point establishment related, this is the Z- part switch quantity output unique question. In order to guarantee in the application has the enough big jump peak-to-peak value, outputs the low level not to send too high, must the appropriate establishment static state operating point, thus when supply voltage certain, the reasonable choice load resistance RL value is extremely important. The Z- part in the power take-off valve signal, namely the work in the M1 zone time, its power loss has not been very small, only then works in the M3 zone time, its power loss only then increases. the switching signal low level is not a constant, because of VOL=IZRL, when temperature increment, IZ increases Ambassador VOL to increase, moreover load resistance RL bigger, the low level increases the 浙江工業(yè)大學(xué)浙西分校信電系畢業(yè)設(shè)計(jì)（中英翻譯） 9 value also in a big way, therefore, in order to reduce VOL, slightly requests RL to be better. As a result of the Z- part power loss limit, RL cannot unlimited reducing, and reduces for the Z- part trouble-free service the power source to consume the electricity, may choose the Z- part the work power loss for the fixed power loss 1/5, namely PZ=0.2PM, PZ=0.2PM=IZVZ=IfVf. Then extracts the appropriate load resistance RL value through the following computation: According to product standard stipulation that, Vf = Vth/3 Takes: VZ=Vf=Vth /3, If= (E-Vf)/RL= (Vth-Vf+IthRL)/RL Because IthRL is very small, ignores (2) supply voltage ES determination ES=VZS+IZSRL = Vth DV+ IZSRL Because IZSRL is very small, only then 0.10.2V, therefore ignores it, under the normal temperature supply voltage ES is: ES Vth DV Considered when to power source voltage regulation, possibly has the error, the reference design DV value cannot excessively be small, its minimum value suggestion for (510C) SP (SP is threshold value temperature sensitivity). Therefore: ES= Vth + (510C) SP (3) Fourth, pulse frequency output temperature compensation 1. applies the electric circuit The Z- part pulse frequency output has the different electric circuit configuration,This electric circuit when supply voltage E is constant, in the light, magnetism or the strength and so on under exterior drive function, out-port VO may output with exterior drove the proportion the pulse frequency signal, is called the effective output, the profile is the saw-tooth wave. As semiconductor sensitive unit, because the ambient temperature also has the certain sensitivity to the effective output, this seriously will affect the effective output the examination precision, when the ambient temperature change big or the examination precision request will be high, will have to warm to float through temperature compensation performs to suppress. 2. temperature compensations principle Z- part output frequency f and working voltage E related, and circuit structure as well as parameter related, also concerns with the use ambient temperature. When the electric circuit structure as well as the parameter are certain (C=0.1mF, RL=15kW) outputs frequency f only concerns with working voltage E and operating temperature T. In order to study the temperature compensation principle, determined the appropriate compensating process, lists three implicit functions relations especially: F = F (T, E) If constitutes the Z- part the frequency output circuit regards as is when a linear system or may carry on linearized processing, may use the principle of superposition to this implicit function as desired parital differential: When the supply voltage changes DE, and overcomes exactly by temperature change DT to when outputs the frequency the influence, the output frequency maintains invariablely, namely Df = 0, then: If supposes: For temperature sensitivity, For voltage sensitivity, Then results in: STDT= - SE DE Compensates the relations for further quota determination voltage E and between temperature T, may define temperature compensation coefficient C is: C/V 浙江工業(yè)大學(xué)浙西分校信電系畢業(yè)設(shè)計(jì)（中英翻譯） 10 Compensates coefficient C the physics significance is, when every time working voltage E changes 1V, can the compensation temperature warm change output frequency f which how many institute causes to float. Obviously, SE bigger, or ST smaller, causes to compensate coefficient C to be bigger, more is advantageous for carries on temperature compensation. Among them, the minus sign the expression for realization temperature compensation, the voltage E change direction should and the temperature change direction is opposite. After compensates the coefficient C determination, may according to compensate the coefficient request design compensating circuit, realization temperature compensation.