摘 要

在现代电子设备生产和研发中，对于提供的激励源的准确度和稳定度以及在测量时的准确度和动态范围的要求越来越高，同时，很多的测试还希望能够在提供源的同时还能进行测量工作。于是，这种具备源/测量功能的仪器数字源表就应运而生了。数字源表能够在提供精密电源的同时进行电信号的测量，这不仅优化了测试复杂度，同时还缩减了测试成本。因此，通过数字源表，测试人员能够很好的进行对待测设备的特征分析以及生产控制。

目前，国外对数字源表技术的研究已经非常成熟，诸如吉时利和安捷伦这些公司基本上控制了数字源表的市场，国外数字源表在源表的稳定性、准确度和工作范围等等性能指标上都是处于领先地位的。相比于国外，虽然我国的数字源表研发技术也在稳步进步中，但是由于我国在数字源表领域的起步较晚，所以对数字源表的技术研究远不如国外，同时生产的数字源表在各方面性能都无法和国外相比。因此，国内急迫的需要研发出一款高性能的数字源表以取代国外产品。

本文的基本研究内容是针对数字源表，研究其在作为源以及测量方面的准确度等关键性能指标的影响因素，首先分析了数字源表源和测量功能的实现方法，然后针对其在实现方法的关键环节以及系统的关键误差来源，主要分析了电源噪声、运放参数、基准电压和采样电阻以及误差电流等对数字源表输出和测量准确度的影响，然后，在基于上述分析的基础上，通过对电路的优化、器件的选择以及测量方法的改进等方面对数字源表关键性能进行了提高。另外，还对上述方法进行了理论上的推导分析，论证了这些方案的可行性。

本文最终完成了对数字源表包括准确的在内的关键性能指标影响因素的分析，从理论上分析了这些影响因素如何且在何种程度上影响了性能指标，并且提出了消除或者改善这些影响因素的有效方法并进行了论证。从而基本上完成了本课题的目标要求。

关键词：数字源表，准确度，直流电源，测量

Abstract

In modern electronic equipment production and R amp; D, accuracy and stability for the excitation source and the measurement accuracy and dynamic range of the increasingly high demand, at the same time, a lot of tests also hope to work in the source can also measure at the same time. As a result, this Sourcemeter with source / measurement functions came into being. Measurement of Sourcemeter to provide precision electrical signals in the power supply at the same time, the equivalent set of current / voltage source and current / voltage meter and resistance meter in one, which not only optimizes the test complexity, but also reduces the test cost. Therefore, through the Sourcemeter, the tester can well handle the characteristic analysis and production control of the measurement equipment.

At present, the research on digital sourcemeter technology in foreign countries has been very mature, such as Keithley and Agilent these companies basically control the market of digital Sourcemeter, digital source of foreign table are at the leading position in the Sourcemeter’s stability, accuracy and working range and performance index. Compared with foreign countries, although China's digital source meter R amp; D technology is also in steady progress, but because of our country in the field of digital source meter started late, so the study on the digital source table than abroad, while the production of digital source table in all aspects of performance can not be compared with foreign countries. Therefore, the urgent need for domestic research and development of a high-performance digital Sourcemeter to replace foreign products.

The basic research content of this paper is to study the digital Sourcemeter, as key performance indicators and measurement accuracy of the source of the influence factors, firstly analyzes the realization method of digital source meter source and measure function, then the key link in the realization method and the key source of error analysis the power supply noise, amplifier parameters, reference voltage and current sampling resistor and the error of digital source meter output and measurement accuracy, and then, on the basis of the above analysis, through the optimization of circuit, device selection and measurement method improvement of digital source meter key performance were improved. In addition, the above methods are theoretically deduced and analyzed, and the feasibility of these schemes is proved.

In this paper, we analyze the influencing factors of the key performance indicators including the accurate source of the digital Sourcemeter, and analyze the influence of these factors on the performance index, and propose to eliminate or improve these effects Factor of the effective method and demonstrated. Which basically completed the objectives of the subject requirements. We finally finish the table analysis on influencing factors of key performance indicators, including the accuracy of Sourcemeter, from the theoretical analysis of the influence of these factors affect the performance of how and to what extent, and put forward to eliminate or ameliorate the effects of effective factors and method are discussed. Thus basically completed the objectives of this topic.

Key words: Sourcemeter, Accuracy, DC power supply, Measurement

目录

摘要 I

Abstract II

目录 IV

第一章 绪论 1

1.1 课题背景及研究意义 1

1.2 国内外研究现状 1

1.3 课题主要内容 2

第二章 影响数字源表性能指标关键因素分析 3

2.1 数字源表性能指标分析 3

2.2 影响数字源表性能指标的关键因素分析 4

2.2.1 源/测量功能实现 4

2.2.2 电源纹波和电源噪声对数字源表输出准确度的影响 4

2.2.3 运算放大器参数对数字源表性能指标的影响分析 7

2.2.4 采样电阻和基准电压的影响 15

2.2.5 误差量对数字源表测量准确度的影响 16

2.3 本章小结 19

第三章 改善数字源表性能指标的方法研究 20

3.1 电容去耦改善电源纹波和噪声 20

3.1.1 电容去耦 20

3.1.2 采用电源去耦电容滤波电路 21

3.1.3 电源纹波抑制器 22

3.2 采样电阻的选择 23

3.3 采用LDO的带隙基准电压源 24

3.3.1 LDO线性稳压器 24

3.3.2 带隙基准电压源 25

3.3.2 LDO与带隙基准电压源结合 26

3.4 利用Delta法消除热电动势 27

3.5 本章小结 29

第四章 总结和展望 31

4.1 全文总结 31

4.2 工作展望 31

致谢 32

参考文献 33

第一章 绪论

1.1 课题背景及研究意义

目前，世界范围内的电子消费品功能越来越丰富，同时其精密度也不断提高，诸如半导体、太阳能电池、高功率LED等等的新型材料需要进行更快更精准以及更方便的测量手段。然而，一般的测量仪器无法满足现在的综合测量要求，数字多用表虽然能进行电压电流测试，但是在面对极低小信号的测量时，无法达到我们对精确度的要求，而诸如皮安计、纳伏表等一起虽然可以满足精确度，但是其功能有限，只能进行单方面电气特性的测量。而现代生产和科学研究的测量要求一种高稳定度、高精确度、高分辨率同时还能具有带负载能力这些关键要素于一体的测量仪器。为了适应现代生产环境和现代科学研究，这种仪器最好能够进行I-V特征分析，从而能够发现表征电子器件的特性。在以前，测量仪器无法同时整合源和测量的功能，这就给上述的测量要求带来很多的麻烦，例如，如果想要测取太阳能电池的I-V曲线，那么，必须分别提供电源、电表、示波器等分立器件，这不仅使得测量工作效率低下，同时也让整个测量空间庞大。在这种现代测量的需求下，数字源表于上世纪80年代产生了，这给整个测量工程带来了福音。数字源表整合了电流源、电压源、电流表、电压表、电阻表，它综合了元和测量的功能，也就是说，它在提供高精度、高稳定度的激励源的同时可以进行精确的电压和电流的测量。此外，数字源表还有更好的测量精度和简洁的图形用户界面，还提供了更为丰富的通讯接口，能够很方便的搭配其他器件进行更复杂的测式工作。凭借着优异的电源和测试能力，数字源表被广泛的应用在电子器件的生产和研发中。^【1】

1.2 国内外研究现状