ADC/DAC(4)- 什么是DAC以及DAC的应用

2018-12-06 10:44:55 来源:电路设计技能
标签:

 

苏老师时不时要让大家阅读一些英文的资料,养成用英文学习和阅读的习惯,毕竟这个行业全球最前沿、最权威的信息都是英文的。今天借“elprocus”上面的一篇综述性的文章介绍一下什么是DAC、DAC的基本构成以及DAC的一些典型应用,有任何问题可以通过留言或者在我们的技术交流群里进行交流,我们明天再说说DAC的一些选型要领。
 
在文章中主要介绍了最常用的两种DAC构成结构,其实我们在很多场景下会采用PWM(脉宽调制)+低通滤波来实现数字量到模拟量的转化,比如开关稳压,关于PWM我也会在以后的文章中专门讲一下。
 
About Digital to Analog Converter (DAC) and Its Applications
Why we need data converters? In the real world, most data are available in the form of analog in nature. We have two types of converters analog to digital converter and digital to analog converter. While manipulating the data, these two converting interfaces are essential to digital electronic equipment and an analog electric device which to be processed by a processor in order produce required operation.
 
For example, take the below DSP illustration, an ADC converts the analog data collected by audio input equipment such as a microphone (sensor), into a digital signal that can be processed by a computer. The computer may add sound effects. Now a DAC will process the digital sound signal back into the analog signal that is used by audio output equipment such as a speaker.
 
语音信号处理
 
Digital to Analog Converter (DAC)
Digital to Analog Converter (DAC) is a device that transforms digital data into an analog signal. According to the Nyquist-Shannon sampling theorem, any sampled data can be reconstructed perfectly with bandwidth and Nyquist criteria.
 
A DAC can reconstruct sampled data into an analog signal with precision. The digital data may be produced from a microprocessor, Application Specific Integrated Circuit (ASIC), or Field Programmable Gate Array (FPGA), but ultimately the data requires the conversion to an analog signal in order to interact with the real world.
 
基本的数字/模拟转换器
 
D/A Converter Architectures
There are two methods commonly used for digital to analog conversion: Weighted Resistors method and the other one is using the R-2R ladder network method.
DAC using Weighted Resistors method
 
The below shown schematic diagram is DAC using weighted resistors. The basic operation of DAC is the ability to add inputs that will ultimately correspond to the contributions of the various bits of the digital input. In the voltage domain, that is if the input signals are voltages, the addition of the binary bits can be achieved using the inverting summing amplifier shown in the below figure.
 
二进制权重的电阻DAC
 
In the voltage domain, that is if the input signals are voltages, the addition of the binary bits can be achieved using the inverting summing amplifier shown in the above figure.
 
The input resistors of the op-amp have their resistance values weighted in a binary format. When the receiving binary 1 the switch connects the resistor to the reference voltage. When the logic circuit receives binary 0, the switch connects the resistor to ground. All the digital input bits are simultaneously applied to the DAC.
 
The DAC generates analog output voltage corresponding to the given digital data signal. For the DAC the given digital voltage is b3 b2 b1 b0 where each bit is a binary value (0 or 1). The output voltage produced at output side is
 
关注与非网微信 ( ee-focus )
限量版产业观察、行业动态、技术大餐每日推荐
享受快时代的精品慢阅读
 

 

继续阅读
STM32如何配置ADC?

配置ADC 1、 系统时钟定义

中国ADC到底是个什么水平?
中国ADC到底是个什么水平?

眼下,中国的集成电路产业正在加紧追赶世界先进水平的脚步,除了像CPU、、GPU、DSP、FPGA这样的核心处理器之外,我们在高性能模拟器件方面,还处于后来学习者的角色。而ADC/DAC是模数混合IC,是连接模拟和数字世界之间的桥梁,具有很高的技术含量。

ADC/DAC (1)- 连接模拟、数字世界的桥,多数工程师被桥隔开
ADC/DAC (1)- 连接模拟、数字世界的桥,多数工程师被桥隔开

前不久一位老朋友写信问我如何提取一个低频模拟信号(不到50KHz)上的调制信息,他用了各种低噪声放大、滤波等等办法,系统搞得非常复杂,稳定性依然很差,手下的工程师对模拟电路也不擅长(估计90%的工程师都是稀里糊涂的)。

8051单片机输出可调 PWM 波的具体做法

PWM 实际上是在单片机的某个引脚输出一系列的矩形波,其周期一般是固定的;而其高电平、低电平所占用的时间,是可以受控调整的。

ADC/DAC(3)- 数字示波器中ADC的选用
ADC/DAC(3)- 数字示波器中ADC的选用

自己动手做一个信号发生器和示波器非常重要,不仅可以深刻理解测量仪器的工作原理、关键技术指标,还可以将书本上学过的模拟电路、数字逻辑乃至嵌入式系统全部串起来,从系统层面对各个部分的功能以及构成有更真切的认识,因此苏老师觉得这两个项目应该是所有电子工程师都要动手做一遍的基础入门项目。

更多资讯
锂电池电芯浆料的工艺和原理分析

锂电池电芯浆料搅拌是混合分散工艺在锂离子电池的整个生产工艺中对产品的品质影响度大于30%,是整个生产工艺中最重要的环节。

三星对在华投资信心饱满,拟在天津投资动力电池和车用MLCC

记者日前从天津方面及三星中国获悉,三星拟在天津调整部分产品结构,同时投资建设全球领先的动力电池生产线和车用MLCC工厂(多层陶瓷电容器)等新项目。

柔宇科技与空中客车签署合作备忘录

2018年12月10日,柔宇科技有限公司(Royole Corporation)与空中客车中国创新中心(Airbus China Innovation Centre,ACIC)在深圳正式签署战略合作备忘录,双方将就柔性电子技术在飞机客舱等场景的应用和商业合作开展研究。

Fluke 6658A直流充电机检定装置闪耀面市

中国,上海——福禄克(FLUKE)公司计量校准部,校准仪器和软件行业的世界领导者,推出了6658A直流充电机检定装置。

以一个13.2W电源为例分享电源原理图及每个元件的功能详解

电源原理图及每个元件的功能详解