浙江工業(yè)大學浙西分校信電系畢業(yè)設計（中英翻譯） 1 高精度正弦全自動激勵信號源的設計與實現(xiàn) 摘要 ： 本文詳細地介紹了光敏 Z-元件、磁敏 Z-元件以及力敏 Z-元件的溫度補償原理與補償方法，供用戶利用光、磁、力敏 Z-元件進行應用開發(fā)時參考。 關鍵詞 ： Z-元件、敏感元件、溫度補償、光敏、磁敏、力敏 一、前言 半導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上，詳細介紹 Z-元件的溫度補償原理與溫度補償方法，供光、磁、力敏 Z-元件應用開發(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 、力等外部激勵作用輸出模擬、開關或脈沖頻率信號 123，其中后兩種為數(shù)字信號，可構成三端數(shù)字傳感器。這種三端數(shù)字傳感器不需放大和 A/D轉換就可與計算機直接通訊，直接用于多種物理參數(shù)的監(jiān)控、報警、檢測和計量，在數(shù)字信息時代具有廣泛的應用前景，這是 Z-元件的技術優(yōu)勢。但由于 Z-元件是半導體敏感元件，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生溫度漂移而嚴重影響檢測精度。因而，在高精度檢測計量中，除在生產工藝上、電路參數(shù)設計上應盡可能降低光、磁、力敏 Z-元件的溫度靈敏度外，還必須研究 Z-元 件所特有的溫度補償技術。 Z-元件的工作原理本身很便于進行溫度補償，補償方法也很多。同一品種的 Z-元件，因應用電路組態(tài)不同，其補償原理與補償方法也不同，特就模擬、開關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償 對 Z-元件的模擬量輸出，溫度補償?shù)哪康氖强朔囟茸兓母蓴_，調整靜態(tài)工作點，使輸出電壓穩(wěn)定。 1應用電路 Z-元件的模擬量輸出有正向應用和反向應用兩種方式。 2溫度補償原理和補償方法 溫度補償時應以標準溫度 20 為溫度補償?shù)墓ぷ骰鶞剩渲辛睿?TS：標準溫度 T：工作溫度 QS：標準溫度時的靜態(tài)工作點 Q：工作溫度時的靜態(tài)工作點 QS：溫度補償后的靜態(tài)工作點 VOS：標準溫度時的輸出電壓 VO：工作溫度時的輸出電壓 浙江工業(yè)大學浙西分校信電系畢業(yè)設計（中英翻譯） 2 在標準溫度 TS 時，由電源電壓 E、負載電阻 RL 決定的負載線與 TS 時的 M1 區(qū)伏安特性（或反向特性）相交，確定靜態(tài)工作點 QS，輸出電壓為 VOS。當環(huán)境溫度從 TS 升高到 T 時，靜態(tài)工作點 QS 沿負載線移動到 Q，相應使輸出電壓由 VOS 增加到 VO，且 VO VOS DVO，產生輸出漂移 DVO，。若采用補償措施在環(huán)境溫度 T 時使工作點由 Q 移動到 QS，使 輸出電壓恢復為 VO，則可抑制輸出漂移，使 DVO 0，達到全補償。 (1)利用 NTC 熱敏電阻 基于溫度補償原理 ， 利用 NTC熱敏電阻 Rt取代負載電阻 RL， 標準溫度 TS 時負載電阻為 Rt，當溫度升高到工作溫度 T時，使其阻值為 Rt，可使靜態(tài)工作點由 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)大學浙西分校信電系畢業(yè)設計（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)大學浙西分校信電系畢業(yè)設計（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.