电源噪声对模数转换器性能的影响  

Influence of power supply noise on the performance of ADC

作　　者：王力[1] 武杰[1] WANG Li;WU Jie(Department of Modern Physics,State Key Laboratory of Particle Detection&Electronics,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学近代物理系核探测与核电子学国家重点实验室,合肥230026

出　　处：《核技术》2020年第11期43-49,共7页Nuclear Techniques

基　　金：国家科技重大专项(No.2017ZX05008-008-041);中国科学院战略性先导科技专项(No.XDC07020403);国家自然科学基金(No.41574106)资助。

摘　　要：供电质量是影响模数转换器(Analog-to-Digital Converter,ADC)性能的重要因素。为了研究电源噪声对ADC的影响,先从理论上分析了电源噪声对ADC性能的影响,然后设计了一个32 bit的低噪声ADC测试电路,利用电源分析仪给ADC电源加入已知频率和振幅的正弦波作为噪声,测试了该电源噪声对ADC性能的影响。测试结果表明:电源噪声会和ADC的输入信号相互调制,产生互调噪声,其中二阶互调噪声为主要成分。ADC供电电源的低频电源噪声更容易进入信号的频率范围内。测试结果还显示:对于具有高电源抑制比的ADC来说,开关电源的纹波和噪声对ADC的性能影响有限,而带有数字滤波器的ADC可以进一步降低电源噪声对ADC性能的影响。因此在追求电源使用效率的场景下,可以直接使用开关电源给ADC供电,而不必使用低压差线形稳压器(Low-Dropout linear regulator,LDO)供电方式。[Background]Power supply quality is an important factor affecting the performance of an analog-todigital converter(ADC).[Purpose]This study aims to explore the influence of power supply noise on the performance of ADC.[Methods]Firstly,the theoretical influence of power supply noise on the performance of ADC was analyzed.Then,a 32 bit low-noise ADC test circuit was designed for power supply analysis.Finally,a sine wave of known frequency and amplitude was taken as noise and overlaid on the ADC power supply to verify the influence of power supply noise on ADC performance.[Results]The test results show that the power supply noise and the input signal of the ADC are mutually modulated to produce intermodulation noise,of which the second-order intermodulation noise is the main component.The low-frequency power supply noise of the ADC power supply is more easily to enter the signal frequency range while the ripple and noise of switching power supplies have limited impact on the performance of the ADC with high power supply rejection ratios.In addition,ADCs with digital filters can further reduce the influence of power supply noise on ADC performance.[Conclusions]In the pursuit of power supply efficiency,it is recommended to use to power the ADC instead of using the low-dropout linear regulator(LDO)power supply,the switch mode power supply can be used to pursue power supply efficiency for ADC.

关 键 词：ADC 电源噪声 调制 

分 类 号：TL81[核科学技术—核技术及应用]