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1.
许思琦 《应用声学》2017,25(4):34-34
对于高速A/D的采集,采用I/O读取方式, ARM9最大能够采集500KSPS的A/D,因此ARM不能实现对更高速度数据读取;为达到更高速,提出了FPGA+ARM的双核架构的高速数据采集的方法,FPGA能够采集2MSPS的A/D,并采用ARM的DMA完成与FPGA的FIFO通信,以及使用Linux的内存映射技术来提高应用层与内核层数据传输效率,完成数据采集。该系统设计了FPGA+ARM接口电路,开发了Linux下的DMA驱动程序。经试验测试,系统具有高速采集的性能。  相似文献   

2.
介绍了一种纳秒级脉冲激光光斑能量分布测量电路的设计方法,采用自动跟踪积分方式,根据预测先将脉冲光电流积分并保存,然后用速度较低的A/D芯片进行A/D转换,该方法避免了采用高速A/D芯片,且可以获得较高的采样分辨率,特别是在需要采集的通道数较多时具有明显优势。  相似文献   

3.
TN386.52006054463高速线阵CCD信号采集电路设计=Design of high speedlinear CCDsignal acquisition circuit[刊,中]/李翰山(西安工业学院电子信息工程学院.陕西,西安(710032)),雷志勇…//西安工业学院学报.—2006,26(2).—136-141为实现高速弹丸信号采集,提出了利用CPLD与高速A/D转换芯片相结合,设计高速高灵敏度的CCD信号采集电路。根据线阵CCD的工作时序和A/D转换速率要求,采用MAX plusⅡ的图形编译软件,自行设计高速线阵IL-E2CCD芯片内部时序,并结合AD9224芯片特点设计与CCD芯片接口的外围驱动与采集电路,采用LVDS技…  相似文献   

4.
一种不需要采样保持电路和编码器电路,结构简单的行波型模数转报器在中国科学院物理所首次研制成功.它全部采用现有国产TTI逻辑器件.可供视频图象信号的模拟数字转换用.在1979年2月研制成功的原理性样机基础上于1979年9月又研制成功一台改进型的13.3MHz,七位满刻度0—2V的A/D.同时研制成功一台电流开关型30MHz,七位的数模转换器D/A.填补了国内快速A/D和D/A方面的空白.目前这一成果已推广到北京市半导体器件研究所试投产.高速行波型A/D和电流开关型D/A研制成功@吕俊锡  相似文献   

5.
详细分析了由x切LiNbO3干涉式共面波导行波调制器阵列构成的模数(A/D)转换器,包括其研究进展。采用保角变换方法分析了梯形共面波导电极参数(包括电极厚度、缓冲层厚度与中心电极和接地电极的边沿倾角β1,βg)与转换器的带宽、损耗、特征阻抗和驱动功率的关系。β1=βg=10°,电极厚度为3μm时,4位A/D转换器的工作带宽为7.3GHz,所需驱动功率为6.7W。数值仿真结果表明,采用梯形共面波导调制器阵列设计分辨率适中的高速A/D转换器是可行的。  相似文献   

6.
针对通用的光栅传感器数据采集系统存在的问题,介绍了一种新型的基于CAN总线的光栅传感器数据采集系统的设计方法。详细介绍了整个系统的硬件电路设计,包括差动放大,整形,用高速A/D转换器进行数据采样,数字信号处理器,CAN总线接口电路设计。同时对系统的特性也作了分析,整个系统具有高速、高准确度、传送距离远等特点。  相似文献   

7.
何晓青  王伟 《光子学报》1999,28(11):1049-1052
本文提出了用时分复用方法实现双光路并行信号的模数转换方案,讨论了保证精度和并行性的条件,如A/D转换器精度、信号的频率和孔径误差等,给出了相应的计算公式,在此基础上,介绍了一种高速双光路并行数据采集系统的设计及其应用。在此系统中,用PLD设计的状态机是实时读取数据的关键部分。  相似文献   

8.
贾亮  王真真  马兴  赵璐 《应用声学》2015,23(11):45-45
对高速数据采集系统进行了研究,基于其采集速率的问题,提出了一种基于FPGA的高速数据采集系统。利用FPGA实现对12bit的A/D转换器ADC12D800的控制,使用其1.6Gsps双沿采样工作模式完成对400MHz以下高频信号的数据采集。通过设计数据存储方式来降低数据传输速率,使数据经USB传至PC机来实现高频信号地实时采集与存储。实验结果表明它可以实时、高效地完成数据采集,可以应用到雷达、通信、电子对抗等领域。  相似文献   

9.
高速模拟数字转换器A/D在视频图像信号的采集和处理系统、活动目标的雷达自动跟踪系统、数码通讯、数码电视、科学实验和工程技术中的快速瞬变过程信息的采集以及电子仪器等现代化科学和现代国防中都有广泛的应用.我们曾用行波型方案,全部采用国产TTL元件研制成功采样速率达13.3MHz,精度七位,满刻度0-2048 mV的高速A/D样机.这里简单介绍这种A/D的原理及它的测试方法,并给出测试结果. 一、工作原理[1、2] 以四位满刻度0-2000 mV为例.图1是一种结构简单,不需要采保电路和编码器的A/D.图中 Td1-Td3是高精度视频延迟线.C1-C4是比较器,D_…  相似文献   

10.
战略性先导科技专项(TMSR)熔盐堆保护系统中,对接收到的信号需要有较高的数据转换精度,并且保护系统中的元器件具有一定的抗辐射能力。文章主要选用16位串行微功耗、高速、高精度ADS8325芯片和ACTEL公司开发基于Flash技术的具有抗辐射性能的现场可编程门阵列FPGA,设计了熔盐堆保护系统中关键的A/D转换和定值比较单元。整个设计方案用Verilog HDL硬件描述语言实现,并在Libero 平台下进行软件编程实现A/D转换的工作时序和定值比较的控制。文章对方案的软硬件进行了描述,同时分析了相应的测试结果。  相似文献   

11.
针对物理实验读出的需求设计了一款低功耗12 bit 30 MSPS逐次比较型模数变换器(Analog-to-Digital Converter,ADC)芯片,为评估其性能指标参数,需进行系统的测试。在本研究工作中构建了测试系统,然后按照IEEE标准进行了系统的测试和分析。测试结果表明,输入信号在基带范围内ADC有效位(Effective Number Of Bit,ENOB)约为9 bit,达到了本版本芯片的设计指标。同时,综合分析静态性能与动态性能测试结果,可以通过优化逐次比较型ADC中电容阵列电容失配参数,进一步提升ADC的非线性指标,为下一版芯片的改进设计提供了参考依据。Aiming at the requirement of readout electronics in physics experiments, a 12 bit 30 MSPS successiveapproximation-register (SAR) analog-to-digital converter (ADC) with low power consumption has been designed. To evaluate the performance of this ASIC, we conducted a series of tests. We set up a test system, and we tested the ADC according to IEEE std 1241-2010. The test results indicate that the effective number of bit (ENOB) of the ADC is around 9 bits when the input signal is in the first Nyquist zone, which has met the design requirements. According to the results of dynamic and static tests of this ADC, we found that the non-linearity performance of this ASIC can be further enhanced by improving the mismatching among the capacitor array, and this provides important information for the design of the second version of this ADC.  相似文献   

12.
在现有硬件基础上,基于BPM测量准确度的需求,在自制的电子学FPGA芯片内,通过Verilog语言实现了一种数字BPM采样数据增益自动校准的设计。首先介绍了自动增益校准模块的系统总体设计;然后对模块的实现方法做了详细说明,设计并搭建了ADC数据自动增益校准测试平台以验证自动增益较准模块的功能;最后介绍了该设计在BPM通道标定中的应用。实验结果表明,该方法可以实现4通道增益一致,使ADC采样后的数据幅度相同,有效解决了由通道增益不一致引起的测量偏差,以及工程应用中ADC数据幅度校准工作量大且难于操作的问题,将在BPM系统通道自动标定中发挥重要作用。  相似文献   

13.
In this paper, a new design of a photonic crystal (PC) all-optical analog-to-digital converter (ADC), which is based on cascaded 3-dB power splitters, is presented. It has been shown that by choosing appropriate threshold values in the output ports of the 3-dB power splitters, a set of unique states corresponding to different power levels of input analog signal can be obtained. It has been demonstrated that based on the proposed approach, the design of 2 and 3-bit PC ADC can be achievable.  相似文献   

14.
为了解决常用数据采集产品体积较大的问题,选用一种体积小,转换速度快的多通道AD转换芯片ADS8638,设计了FPGA与芯片间的接口电路,并采用verilog语言编写了控制程序,以控制ADS8638芯片对各通道输入的模拟量进行AD转换。通过软件仿真验证、静态时序分析,仿真和分析结果表明,该软件功能、性能、时序正确。最后,将软件经过综合、布局布线后下载到ACTEL FPGA芯片中进行硬件系统测试,测试结果表明,本技术方案设计合理,功能可靠,降低了常用数据采集系统的体积和功耗,具有良好的实用价值。  相似文献   

15.
We have demonstrated the performance of a novel design for a single wavelength 2-bit all-optical analog-to-digital converter (ADC). This converter consists of two high efficient channel drop filters with a coupled cavity-based wavelength selective reflector in a 2D photonic crystal with total length of 15.87 μm. The A/D conversion is achieved by using nonlinear Kerr effect in the cavities. The output ports switch to state ‘1’ at different input power levels to generate unique states preferred for an ADC. This conversion is simulated by the finite difference time domain (FDTD) method for 5 different power levels. The proposed structure can function as a two-bit ADC with a 60 mW/μm input pulse and its maximum sampling rate is found to be ~ 45 GS/s.  相似文献   

16.
We have designed and fabricated a 16-channel Waveform Sampling ASIC for radiation detection and measurement. Waveform sampling is very important for the pulse shape analysis and discrimination, which is often used in radiation detection to discriminate different radiations such as alpha, beta and gamma rays. One channel of the fabricated ASIC consists of a charge-sensitive preamplifier, a VGA (Variable Gain Amplifier), an ADC (Analog to Digital Converter) and digital circuits. The preamplifier converts the current signal to the voltage signal, and the VGA amplifies the signal to appropriate level for the ADC. The ADC was designed to digitize the waveform with a frequency of 100 MHz and a resolution of 6bits. Digital circuits consist of a free-running ADC and a multiplexer which were designed to convert a digitized 100 MHz/6bit signal to a 200 MHz/3bit one, which is effective for the reduction of the number and for the achievement of the high integration in one chip. This chip was designed and fabricated with 0.35 μm CMOS technology by ROHM and the size of the ASIC is 4.9 mm by 4.9 mm. The design concept and some experimental results are shown in this paper.  相似文献   

17.
为了实现对高重频硬X射线自由电子激光装置(SHINE)条带型BPM(Beam Position Monitor)系统信号的数字化采样和处理,研制了高重频束流采集处理器原型样机。处理器拥有四通道输入,最高达1 GSps的采样率,16 bit采样位数,采用XILINX公司带有嵌入式CPU(Central Processing Unit)的ZYNQ系列FPGA(Field Programmable Gate Array),可以运行Linux系统,同时可以实现高速采样数据的缓存与读出。处理器采用子母板结构设计,子板为ADC(Analog To Digital Converter)采样板,母板为FPGA数字处理板,子母板通过FMC(FPGA Mezzanine Card)接口进行数据传输。ADC采用JESD204B协议进行数据传输,子母板间通过16对差分信号连接通道,最大总传输速率达到80 Gbps。ADC采样数据传入数字母板后,经过FIFO和DDR的缓存,最后通过TCP/IP协议由RJ45接口传输到上位机进行处理和分析,RJ45接口的数据传输速率约为900 Mbps。经过测试,ADC采集子板的带宽高于480 MHz,且在480 MHz带宽内有效位高于10位。FPGA数字母板运行经Petalinux编译的Linux系统,可以实现对连续或者触发模式下,四通道一百万个采样点的存储与数据传输。整个设计可以满足设计要求。  相似文献   

18.
Water diffusion measurements were performed on rabbit Achilles tendons during static tensile loading and tendons in an unloaded state. The apparent diffusion coefficient (ADC) was measured along two directions: parallel and perpendicular to the long axis of the tendon. Tendons were studied after being prepared in two ways: (a) after being stored frozen in phosphate-buffered saline (PBS) and (b) freshly isolated. Statistically significant directional anisotropy was observed in the ADC in all tendons. The ADC was significantly greater in the direction parallel to the long axis of the tendon than in the perpendicular direction. The anisotropy is attributed to the greater restrictions seen by the water molecules in the perpendicular direction and is consistent with the known geometry of the tendon. Storage in PBS caused tendons to swell. This increased the ADC measured along both directions and reduced the anisotropy. The existence of anisotropy in the ADC was not related to the orientation of the specimen in the magnet. The ADC increased along both directions following the application of a 5-N tensile load; the increase was greatest along the perpendicular axis of the tendon. In order to determine whether load-related changes in the ADC reflected changes in interfibrilar spacing, we used electron microscopy to measure load-related changes in fibril spacing. Load-related changes in fiber spacing could not account for the observed changes in the ADC. The increase in ADC caused by loading was attributed to the extrusion of tendon water into a bulk phase along the outside surface of the tendon. In PBS-stored samples, enough fluid was extruded that it could be visualized. The transient response of the ADC to a 5-N tensile load was also studied. The absolute ADC in both directions increased with loading and recovered to baseline upon unloading. The transient changes in ADC, for both loading and unloading, had a mean time constant of approximately 15 min. The magnitude of the load-induced transient ADC changes was comparable to that seen in the static-loading experiments.  相似文献   

19.
Prostate cancer detection using diffusion-weighted imaging is highly affected by the accuracy of the apparent diffusion coefficient (ADC) values in an image. Echo planar imaging (EPI) is a fast sequence commonly used for diffusion imaging but has inherent magnetic susceptibility and chemical shift artefacts associated. A diffusion sequence that is less affected by these artefacts is therefore advantageous. The half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence was chosen. The diffusion sequences were compared in image quality, repeatability of the ADC value and the effect on the ADC value with varied b values. Eight volunteers underwent three scans of each sequence, on a 1.5-T Siemens system, using b values of 0, 150, 300, 450, 600, 750, 900 and 1000 s/mm(2). ADC maps were created to address the reproducibility of the ADC value when using two b values compared to eight b values. The ADC value using all b values with the HASTE sequence gave the best performance in all tested categories. Both sequences gave significantly different ADC mean values for two b values compared to when using eight b values (P<.05) suggesting larger error is present when using two b values. HASTE was shown to be an improvement over EPI in terms of repeatability, signal variation within a region of interest and standard deviation over the volunteer set. The improved accuracy of the ADC value in the HASTE sequence makes it potentially a more sensitive tumor detection technique.  相似文献   

20.
介绍了数字BPM算法的原理和架构,并基于高能物理研究所自制的数字BPM硬件平台获取了BEPC Ⅱ束流流强为600 mA条件下的ADC采样数据。然后在MATLAB环境中设计了NCO模块、CIC滤波器、FIR滤波器以及BEPC Ⅱ束流逐圈位置数据计算模块,并给出了各模块的具体设计参数。最后通过实际ADC数据对各算法模块进行检验,给出了各模块处理后的频域分析结果,并得到了实际束流下水平方向和垂直方向上的逐圈位置分辨率分别为4.55 μm和4.28 μm,为FPGA在线算法的实现与优化提供了可靠的理论依据。  相似文献   

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