单片机和模／数（A／D）转换器的接口

数据采集是各种智能仪表、工控系统、科学试验等工作中必不可少的任务,它是将实时变化的各种物理量如温度、压力、流量等先经过各种传感器和变换器变成电压或电流信号,再经过模数转换器(以下简称A/D)变成数字信号,送到单片机或微机进行运算、显示、打印、控制等处理。现在很多单片机内部已经嵌入了A/D,简化了硬件设计,但是这种A/D的精度一般仅为10位或8位,满足不了一些要求较高的应用需求。本文将以80C31单片机和AD574A的接口为例,从硬件设计和编程两方面介绍如何实现单片机和A/D的接口。希望读者通过本文的介绍可以系统了解A/D转换的过程以及相关的其它技术问题。     

单片机与数/模(D/A)转换器的接口

<正> 单片机是中文译名,其真正的英文名字为Mi。Ontroer(微控制器),可想而知,单片机的控制功能应该是较强的。事实正是如此,单片机从电路设计到指令功能都体现了适用于控制的特点,谈到控制,这就要求单片机不仅能输出开关量去驱动继电器类的开关控制量,还常常需要输出模拟量,如在工业控     

高性能模／数转换器在应力测试中的应用

介绍AD7731型高性能模／数转换器件的主要特点和工作原理，叙述了其在应力测试中与单片机的接口电路和软件设计。详细讨论了使用AD7731的几项关键技术。     

模／数转换器MAX125在数字信号处理器中的应户

介绍MAXIM分司推出的2组各4路输入通道、250kHz采样速率的MAX125型转换器的性能特点、引脚功能，描述MAX125与DSP的一种简洁、新颖的接口方法，同时用C语言编写了的数据采集的应用程序。     

模／数转换器在仪器仪表中的应用

简要介绍12位串行模／数转换器TLC2543的特点及在仪器仪表中的应用，给出与单片机的接口电路：     

不用激光修调的高速12位D／A转换器

传统的集成12位D/A转换器要求用精密的薄膜电阻网络和电阻的激光修调技术。本文介绍的分段设计技术只需要采用常规的高速双极数字IC工艺,采用扩散电阻方法,不需要微调技术,就能保证其D/A的单调性。它比用激光修调的R—2R薄膜电阻网络结构的12位D/A转换器具有更均匀的台阶尺寸,其电阻的精度要求也比后者放宽了8倍;由于内部采用了ECL电路的结构形式,工作速度快,其建立时间在80～100ns。     

一种12位高速低失真数字/模拟转换器的设计

介绍了一种12位高速、低失真数字/模拟转换器(DAC)的设计原理及其电路结构;着重阐述了去毛刺技术及其应用。采用2μm等平面隔离互补双极工艺模型参数进行了Cadence仿真。结果表明,该12位DAC在高达60MHz数据更新率下具有低于100pV·s的毛刺脉冲面积。     

微机械数志换器的原理与应用

微机械数模转换器是一种用数字信号精确控制微执行器输出的新方法,本文介绍了微机械数模转换器的概念,分析了“C－2C梯型网络”,“逐级衰减”两种实现方案的基本原理和结构,对它们的误差,最大分辨率等特性进行了分析,最后对微机数模转换器应用领域和下一步的发展进行展望。     

高速高精度D／A转换电路的激光动态修调

本文介绍了激光修调原理、动态修调实现的方法，并以修调ＳＤＡ１２１０（１２位Ｄ／Ａ转换电路）为例，说明Ｄ／Ａ转换电路动态修调程序设计的方法、技巧以及应注意的问题。     

一种16位高速D/A转换器的研究

介绍了一种16位高速D／A转换器的电路设计、工艺制作和测试结果。该电路为高性能数字／模拟混合电路，工作电压士5．0V，转换速率≥30MSPS，建立时间50ns，增益误差士8％FSR，积分非线性误差LSB，并行输入类型，电流工作模式，功耗500mW，采用2．0μm BiCMOS工艺制作。该工艺包括减压薄外延、高压氧化等平面隔离、可修调SiCr电阻、双层金属布线、12次离子注入、21次光刻。NPN晶体管特征频率fT为4．0GHz；CMOS管的栅氧化层为30nm，耐压为12．0V。     

SDA7533D／A转换器的研制

本文主要讨论了ＳＤＡ７５３３Ｄ／Ａ转换器的工作原理，对其制造工艺进行了详细的研究，最后给出了用优化工艺制造的电路的指标。     

一种8位高速硅D/A转换器的设计

介绍了一种电流舵结构的单调乘法型8位高速硅D／A转换器。着重讨论了为实现高速而采用的全差分电流开关和电流分裂技术及3μm双极工艺。模拟测试结果证明了设计的正确性。     

高速D/A转换器动态参数测试方法研究

对基于逻辑分析仪和频谱分析仪的高速D/A转换器的动态参数测试方法进行了理论分析和测试实践。通过编程,由逻辑分析仪给D/A转换器提供单一频率的数字正弦波和时钟信号;通过频谱分析仪,对D/A转换器输出模拟信号采样,进行快速傅里叶变换,分析得到D/A转换器的动态参数特性。实验证明,该方法能快速测试高速D/A转换器的动态参数,在实际应用中可获得良好的效果。     

A Fast Settling HBT Reference Amplifier for High Speed Digital-to-Analog Converters

This paper proposes a fast settling reference amplifier for use with a current-steering Digital-to-Analog Converter (DAC). The reference amplifier utilizes an open loop architecture, resulting in a bandwidth of 2.5 GHz, small chip area and low power. The wide bandwidth of the reference amplifier is shown to be important for fast settling of DAC current output. The reference amplifier is also able to generate a reference current that tracks fast changes of reference voltage, thus is useful in applications such as multiplying DACs and transversal filters. The proposed design was fabricated using a 1 μm GaAs HBT process. The prototype reference amplifier achieves a temperature coefficient of 92 ppm/°C over a temperature range of 0–100°C and the reference current changes only ±2.14% when the power supply varies ±0.2 V.Yihong Dai received his B.S. and M.Eng. degrees in Electrical Engineering from Shanghai JiaoTong University, Shanghai, China in 1993 and 1996, respectively. From 1996 to 1998, he enjoyed his industrial experiences in Shanghai with semiconductor companies like Shanghai Nortel Semiconductor and Motorola Electronics (China) Shanghai Branch. Since 1998, he has been a research assistant at the Analog and Mixed-signal Laboratory of the Electrical Engineering Department of Brigham Young University working toward his Ph.D. During the summer of 1999, he was with AMI semiconductor Utah Research and Design Center where he developed a threshold voltage based CMOS voltage reference architecture. In the summer of 2001, he was with Ultra Design LLC where he designed a reference amplifier for high speed digital-to-analog converters. His research interest includes voltage reference, reference amplifier and high speed data converters in both CMOS and GaAs processes.Donald T. Comer received the B.S., M.S., and Ph.D. degrees from San Jose State University, the University of California (Berkeley), and the University of Santa Clara, respectively, all in electrical engineering. He began teaching at San Jose State University in 1961 and mixed his teaching and industrial work until he left San Jose State University in 1979. He has worked for California Technical Industries, IBM Corp., Mobility Systems, Precision Monolithics, Storage Technology Corp., and Analog Devices during his career. He founded the AMI Utah Research and Design Center in 1998 that specializes in MOS design. In 2002, Dr. Comer founded Ultra Design, a design center that specializes in high-frequency heterojunction circuit designs. He holds fifteen patents and has published over 50 articles dealing with solid-state and integrated circuits. He has published five textbooks in the field of large-signal and integrated circuits. He formerly held the Quentin Berg Chair at Penn State Harrisburg from 1990 to 1995. He is now a professor of electrical and computer engineering at Brigham Young University where he held the Endowed Chair of Engineering from 1995 to 1998.David J. Comer received the B.S., M.S., and Ph.D. degrees from San Jose State University, the University of California (Berkeley), and Washington State University, respectively, all in electrical engineering. He has worked for IBM Corp., Pacific Electromagnetics, Lawrence Livermore Laboratories, and Intel Corporation. He began his teaching career at the University of Idaho and has taught at the University of Calgary and California State University, Chico. He is presently a professor of electrical and computer engineering at Brigham Young University. He served as Chairman of the Division (Dean) of Engineering at CSU, Chico and as Department Chair at BYU.While at CSU, Chico, Dr. Comer served on the statewide Engineering Liaison Committee and served as Chair of the Council of California State University Deans of Engineering.Dr. Comer has published twelve textbooks and over 60 articles in the field of circuit design. He has contributed sections to the Encyclopedia of Physical Science and Technology and holds seven patents. He was given the Professional Achievement Award at CSU, Chico and was named the Outstanding Teacher of Engineering at BYU. He has also held the College of Engineering Research Chair at Brigham Young University.     

基于权值的微机械数模转换器

提出了一种新颖的基于权值的微机械数模转换器 ,它的原理与电路中的权电阻数模转换器类似。通过改变纵向梁的长度获得不同的刚性值作为比例因子 ,从而实现由二进制电压输入到模拟位移输出的转换。为了减小误差 ,对结构作了优化设计 ,同时还考虑并解决了零稳定性问题 ,提高了输出位移的精度。文中给出了有限元方法对由热执行器阵列驱动的数模转换器的输出位移分析的结果 ,并对几种微机械数模转换器的设计进行了比较。