[经验]

ADC/DAC的基础知识

2018-11-1 15:54:53

4702 adc 寄存器

本博客旨在涵盖“ADC / DAC教程”一文中所述的一般概念。
本文介绍了不同类型的ADC / DAC架构，以及选择ADC或DAC时需要关注的一些关键事项。
我个人不得不在几个项目中使用ADC和DAC。
一个值得注意的项目是SPEC Sensors一氧化碳探测器，它涉及一个带模拟输出的传感器，必须通过ADC运行到我的Arduino Uno。
涉及某种与现实世界接口的传感器的大多数应用通常都涉及ADC。
DAC非常适用于将MCU或微处理器连接到模拟设备，例如使用VoIP的耳机中的扬声器。
图1：ADC架构的比较（由Analog Devices提供）
本文中描述的架构是：
逐次逼近寄存器（SAR）ADC
Sigma Delta（ΣΔ）转换器ADC
流水线转换器ADC
二进制加权DAC
串DAC
R-2R DAC
逐次逼近寄存器，SAR
最受欢迎
经常使用I2C或SPI接口（有时并行）
名称来自于如何使用逐次逼近来确定值
Sigma Delta，ΣΔ
适用于高分辨率应用
使用过采样
使用数字过滤
流水线
最快的ADC
使用子ADC / DAC可轻松转换最高有效位和最低有效位
非常适合高速应用
二进制加权DAC
使用电阻系统，其输出全部满足相同的求和电阻
更高有效位比低有效位输出更多电流
通常用于向学生解释DAC操作
串DAC
最简单的DAC架构
与每个节点的输出串联的等值电阻串
最小的线性
R-2R
很受欢迎的建筑
名称来自事实，即仅使用两个电阻值
非常可扩展
图1来源：http：//www.analog.com/en/analog-dialogue/articles/the-right-adc-architecture.html

以上来自于谷歌翻译

以下为原文

This blog is meant to cover the general concepts written about in the “ADC/DAC Tutorial” article. The article covers different kinds of ADC/DAC architectures, along with some of the key things to look for when choosing an ADC or DAC. I have personally had to use ADCs and DACs for several projects. A notable project was the SPEC Sensors Carbon Monoxide detector which involved a sensor with an analog output that had to be run through an ADC to my Arduino Uno. Most applications involving some kind of sensor that can interface with the real world will usually involve an ADC. DACs are very common for interfacing an MCU or Microprocessor to an analog device, like a speaker in a headset using VoIP.
Figure 1: Comparison of ADC Architectures (Courtesy of Analog Devices)
The architectures described in the article are:

Successive Approximation Register (SAR) ADC
Sigma Delta (∑∆) converter ADC
Pipelined converter ADC
Binary Weighted DAC
String DAC
R-2R DAC Successive Approximation Registers, SAR
Most popular
Often use I2C or SPI interface (sometimes parallel)
Name comes from how value is determined by using successive approximation Sigma Delta,∑∆
Popular for high-resolution applications
Use oversampling
Use digital filtering Pipelined
Fastest ADC
Uses sub ADC/DAC to easily convert most significant bits and least significant bits
Great for high speed applications Binary Weighted DAC
Uses system of resistors whose outputs all meet at same summing resistor
More significant bits output more current than less significant bits
Usually used to explain DAC operation to students String DAC
Simplest DAC architecture
String of equal valued resistors in series with output at each node
Least linear R-2R
Very popular architecture
Name comes from fact that only two values of resistors are used
Very scalable