以某高速实时频谱仪为应用背景，论述了5 Gsps采样率的高速数据采集系统的构成和设计要点，着重分析了采集系统的关键部分高速ADC（analog to digital，模数转换器）的设计、系统采样时钟设计、模数混合信号完整性设计、电磁兼容性设计和基于总线和接口标准（PCI Express）的数据传输和处理软件设计。在实现了系统硬件的基础上，采用Xilinx公司ISE软件的在线逻辑分析仪（ChipScope Pro）测试了ADC和采样时钟的性能，实测表明整体指标达到设计要求。给出上位机对采集数据进行处理的结果，表明系统实现了数据的实时采集存储功能。
上传时间： 2014-11-26
上传用户：黄蛋的蛋黄
This unique guide to designing digital VLSI circuits takes a top-down approach, reflecting the natureof the design process in industry. Starting with architecture design, the book explains the why andhow of digital design, using the physics that designers need to know, and no more.Covering system and component aspects, design verification, VHDL modelling, clocking, signalintegrity, layout, electricaloverstress, field-programmable logic, economic issues, and more, thescope of the book is singularly comprehensive.
标签： Integrated Digital Circuit Design
上传时间： 2013-11-04
上传用户：life840315
The LM20, LM45, LM50, LM60, LM61, and LM62 are analog output temperature sensors. They have various output voltage slopes (6.25mV/°C to 17mV/°C) and power supply voltage ranges (2.4V to 10V).The LM20 is the smallest, lowest power consumption analog output temperature sensor National Semiconductor has released. The LM70 and LM74 are MICROWIRE/SPI compatible digital temperature sensors. The LM70 has a resolution of 0.125°C while the LM74 has a resolution of 0.625°C. The LM74 is the most accurate of the two with an accuracy better than ±1.25°C. The LM75 is National’s first digital output temperature sensor, released several years ago.
上传时间： 2014-12-23
上传用户：yl8908
Differential Nonlinearity: Ideally, any two adjacent digitalcodes correspond to output analog voltages that are exactlyone LSB apart. Differential non-linearity is a measure of theworst case deviation from the ideal 1 LSB step. For example,a DAC with a 1.5 LSB output change for a 1 LSB digital codechange exhibits 1⁄2 LSB differential non-linearity. Differentialnon-linearity may be expressed in fractional bits or as a percentageof full scale. A differential non-linearity greater than1 LSB will lead to a non-monotonic transfer function in aDAC.Gain Error (Full Scale Error): The difference between theoutput voltage (or current) with full scale input code and theideal voltage (or current) that should exist with a full scale inputcode.Gain Temperature Coefficient (Full Scale TemperatureCoefficient): Change in gain error divided by change in temperature.Usually expressed in parts per million per degreeCelsius (ppm/°C).Integral Nonlinearity (Linearity Error): Worst case deviationfrom the line between the endpoints (zero and full scale).Can be expressed as a percentage of full scale or in fractionof an LSB.LSB (Lease-Significant Bit): In a binary coded system thisis the bit that carries the smallest value or weight. Its value isthe full scale voltage (or current) divided by 2n, where n is theresolution of the converter.Monotonicity: A monotonic function has a slope whose signdoes not change. A monotonic DAC has an output thatchanges in the same direction (or remains constant) for eachincrease in the input code. the converse is true for decreasing codes.
标签： Converters Defini DAC
上传时间： 2013-10-30
上传用户：stvnash
ANALOG INPUT BANDWIDTH is a measure of the frequencyat which the reconstructed output fundamental drops3 dB below its low frequency value for a full scale input. Thetest is performed with fIN equal to 100 kHz plus integer multiplesof fCLK. The input frequency at which the output is −3dB relative to the low frequency input signal is the full powerbandwidth.APERTURE JITTER is the variation in aperture delay fromsample to sample. Aperture jitter shows up as input noise.APERTURE DELAY See Sampling Delay.BOTTOM OFFSET is the difference between the input voltagethat just causes the output code to transition to the firstcode and the negative reference voltage. Bottom Offset isdefined as EOB = VZT–VRB, where VZT is the first code transitioninput voltage and VRB is the lower reference voltage.Note that this is different from the normal Zero Scale Error.CONVERSION LATENCY See PIPELINE DELAY.CONVERSION TIME is the time required for a completemeasurement by an analog-to-digital converter. Since theConversion Time does not include acquisition time, multiplexerset up time, or other elements of a complete conversioncycle, the conversion time may be less than theThroughput Time.DC COMMON-MODE ERROR is a specification which appliesto ADCs with differential inputs. It is the change in theoutput code that occurs when the analog voltages on the twoinputs are changed by an equal amount. It is usually expressed in LSBs.
上传时间： 2013-11-12
上传用户：pans0ul
•Founded in Jan. 08, 2001 in Shanghai, China.•Fabless IDH focused on Analog & Mixed Signal Chip design & marketing •Over 100 IC introduced.•Over 200 OEM Customer worldwide•ISO-9000 Certified•Distribution Channel in Taiwan, China & Japan To achieve 100% customer satisfactionby producing the technically advanced product with the best quality, on-time delivery and service. Leverages on proprietary process and world-class engineering team to develop innovative & high quality analog solutions that add value to electronics equipment.
标签： Circuit Analog Design Porta
上传时间： 2013-10-24
上传用户：songnanhua
设计了一种基于PIC16C71单片机的数字水温配制阀。该配制阀采用NTC热敏电阻作温度传感器，与固定电阻组成简单分压电路作为水温测量电路，利用PIC16C71单片机内置的8位A/D转换器把热敏电阻上的模拟电压转换为数字量，PIC16C71单片机控制直流电机驱动混水阀调节冷热水的混合比例实现水温调节。给出了控制电路图，对水温测量电路的参数选择和测温精度作了详细讨论。实验和分析表明，选用阻值较大的NTC热敏电阻和分压电阻可较好地解决热敏电阻因功耗较大造成的热击穿问题。 Abstract: A digital valve for controlling water temperature based on PIC16C71 was presented in this paper.A bleeder circuit which consisted of a NTC thermistor as temperature sensor and a fixed resistance was designed as water temperature measuring circuit.The analog voltage on the thermistor was converted into digital signal by a 8-bit A/D converter embedded in PIC16C71. Based on the digital signal， the MCU PIC16C71 drived the valve by a DC motor to adjust the water temperature through adjusting the proportion of hot water and cold water.The circuit diagram of controller was given，the principle，the component parameters and the accuracy of measuring temperatures were also dissertated in detail. It was found by experiment and analysis that thermal breakdown of thermistor caused by high power could be solved by selecting thermistor and fixed resistance with high impedance value.
上传时间： 2013-11-08
上传用户：Yue Zhong
为提高电容测量精度，针对电容式传感器的工作原理设计了基于PIC16LF874单片机电容测量模块。简单阐述了电容测量电路的应用背景和国内外研究现状，介绍了美国Microchip公司PIC16LF874单片机的特性。电容式传感器输出的动态微弱电容信号通过PS021型电容数字转换器把模拟量数据转换成数字量数据，所测数据由PIC16LF874单片机应用程序进行处理、显示和保存。实验结果表明，固定电容标称值为10~20 pF 的测量值相对误差在1%以内，同时也可知被测电容容值越大，测量值和标称值相对误差越小。 Abstract: To improve the accuracy of capacitance measurement，aimed at the principle of work of mercury capacitance acceleration transducer，the design of micro capacitance measurement circuit is based on the key PIC16LF874 chip. Briefly discusses the application of the capacitance measuring circuit for the background and status of foreign researchers，focusing on the United States PIC16LF874 microcontroller features. Capacitive sensor outputed signal through the dynamics of weak PS021-chip capacitors （capacitancedigital converter） to convert analog data into digital data，the measured data from the PIC16LF874 microcontroller application process， display and preservation. Experimental results show that the fixed capacitor 10pF ~ 20pF nominal value of the measured value of relative error is within 1%，but also it canbe seen the value of the measured capacitance larger，measuring value and the nominal value of relative error smaller.
上传时间： 2013-10-29
上传用户：wojiaohs
详细介绍了TLC1549系列模数转换器的特点及工作原理，然后根据TLC1549的工作时序和A/D转换原理针对实际问题编写了详细的汇编语言程序。 Abstract: A basic principle and characteristic of TLC1549 analog-to-digital converter are introduced? detailedly in this article.Through engineering-oriented illustration,a microcomputer programmer base on basic principle and time sequence of TLC1549 is writted.
上传时间： 2014-07-16
上传用户：blans
Luminary Micro provides an analog-to-digital converter (ADC) module on some members of theStellaris microcontroller family. The hardware resolution of the ADC is 10 bits; however, due to noiseand other accuracy-diminishing factors, the true accuracy is less than 10 bits. This application noteprovides a software-based oversampling technique, resulting in an improved Effective Number OfBits (ENOB) in the conversion result. This document describes methods of oversampling an inputsignal, and the impact on precision and overall system performance.
标签： Oversampling Techniques ADC fo
上传时间： 2013-12-17
上传用户：zhyiroy
