外文翻译--高精度正弦全自动激励信号源的设计与实现

浙江工业大学浙西分校信电系毕业设计（中英翻译） 1 高精度正弦全自动激励信号源的设计与实现 摘要 ： 本文详细地介绍了光敏 Z-元件、磁敏 Z-元件以及力敏 Z-元件的温度补偿原理与补偿方法，供用户利用光、磁、力敏 Z-元件进行应用开发时参考。 关键词 ： Z-元件、敏感元件、温度补偿、光敏、磁敏、力敏 一、前言 半导体敏感元件对温度都有一定的灵敏度。抑制温度漂移是半导体敏感元件的常见问题， Z-元件也不例外。本文在前述文章的基础上，详细介绍 Z-元件的温度补偿原理与温度补偿方法，供光、磁、力敏 Z-元件应用开发参考。 不同品种的 Z-元件均能以简单的电路，分别对温、光、磁 、力等外部激励作用输出模拟、开关或脉冲频率信号 123，其中后两种为数字信号，可构成三端数字传感器。这种三端数字传感器不需放大和 A/D转换就可与计算机直接通讯，直接用于多种物理参数的监控、报警、检测和计量，在数字信息时代具有广泛的应用前景，这是 Z-元件的技术优势。但由于 Z-元件是半导体敏感元件，对环境温度影响必然也有一定的灵敏度，这将在有效输出中因产生温度漂移而严重影响检测精度。因而，在高精度检测计量中，除在生产工艺上、电路参数设计上应尽可能降低光、磁、力敏 Z-元件的温度灵敏度外，还必须研究 Z-元 件所特有的温度补偿技术。 Z-元件的工作原理本身很便于进行温度补偿，补偿方法也很多。同一品种的 Z-元件，因应用电路组态不同，其补偿原理与补偿方法也不同，特就模拟、开关和脉冲频率三种不同的输出组态分别叙述如下。 二、模拟量输出的温度补偿 对 Z-元件的模拟量输出，温度补偿的目的是克服温度变化的干扰，调整静态工作点，使输出电压稳定。 1应用电路 Z-元件的模拟量输出有正向应用和反向应用两种方式。 2温度补偿原理和补偿方法 温度补偿时应以标准温度 20 为温度补偿的工作基准，其中令： TS：标准温度 T：工作温度 QS：标准温度时的静态工作点 Q：工作温度时的静态工作点 QS：温度补偿后的静态工作点 VOS：标准温度时的输出电压 VO：工作温度时的输出电压 浙江工业大学浙西分校信电系毕业设计（中英翻译） 2 在标准温度 TS 时，由电源电压 E、负载电阻 RL 决定的负载线与 TS 时的 M1 区伏安特性（或反向特性）相交，确定静态工作点 QS，输出电压为 VOS。当环境温度从 TS 升高到 T 时，静态工作点 QS 沿负载线移动到 Q，相应使输出电压由 VOS 增加到 VO，且 VO VOS DVO，产生输出漂移 DVO，。若采用补偿措施在环境温度 T 时使工作点由 Q 移动到 QS，使 输出电压恢复为 VO，则可抑制输出漂移，使 DVO 0，达到全补偿。 (1)利用 NTC 热敏电阻 基于温度补偿原理 ， 利用 NTC热敏电阻 Rt取代负载电阻 RL， 标准温度 TS 时负载电阻为 Rt，当温度升高到工作温度 T时，使其阻值为 Rt，可使静态工作点由 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 浙江工业大学浙西分校信电系毕业设计（中英翻译） 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,