Types of analog to digital converter
The voltage divider in figure 3 has a total resistance of 8R. The flash method uses comparators that compare reference voltages with the analog input voltage.įigure 3 depicts a diagram of a 3-bit flash analog to digital converter.Īs we can see, the circuit consists of a resistive voltage divider, seven analog comparators, a priority encoder, and an output latch. Types of Analog to Digital ConvertersĪlso known as the simultaneous or parallel analog to digital converter, the flash ADC gets its name from its main strength - speed.
![types of analog to digital converter types of analog to digital converter](https://s2.studylib.net/store/data/005615348_1-d0d3873002f071572028aaa653494bf1-768x994.png)
Now that we have some general info on analog to digital converters, let’s go over the most common ones around today. If we take more samples and reduce the sampling period, the red signal will get smoother and look more like the original sine wave. Notice how it sort of has the same shape as the sine wave (in blue). The time in between samples is the sampling period.įigure 2: if we connect the samples in figure 1 with horizontal lines, we’ll get a staircase like this (in red). Explaining why the Nyquist theorem works and finding frequency components of signals involves a lot of high-level math which is beyond the scope of this article, but perhaps a future post will cover the Nyquist sampling theorem in a bit more detail.įigures 1 and 2 offer a basic graphical depiction of sampling an analog signal.įigure 1: sampling an analog signal. The Nyquist theorem says that to avoid any loss of information the sampling rate must be at least twice as high as the highest frequency component we expect to see in the analog signal we’re sampling. This rate is governed by the Nyquist theorem. I’ll assume you know the difference from here on.Īnalog signals continuously vary with time, so to convert an analog signal into digital form an ADC must sample the analog signal at a certain rate or frequency.
![types of analog to digital converter types of analog to digital converter](https://slideplayer.com/slide/3252260/11/images/8/In+our+experiment+ADC0804+%2C+and+the+SAR+ADC+are+explained..jpg)
Often, the analog to digital converters you’ll work with are part of the microcontroller or board of choice but ADCs in separate IC packages are available for certain applications.īy the way, if you’re not 100% sure what the difference between digital and analog is, I urge you to see Analog vs Digital: What’s the Difference? In other words, an ADC takes a continuous analog input signal and converts it into a binary number which a computer or microcontroller can work with. That’s enough history for now, let’s talk about how ADCs work.Īn analog to digital converter or ADC, transforms analog information in electrical form into digital data. Technology certainly has come a long way, hasn’t isn’t it? It sold for $8,500 at the time which, according to some online inflation calculators, translates to more the $80,700 in 2019 dollars. (70 kg) and slurped up at least 500 watts of power, often times more. Toward that end, according to the Data Conversion Handbook by Walt Kester, the first commercial ADC showed up on the scene in 1954. Sometimes, I start my posts with an interesting historical tidbit. How the Analog to Digital Converter Works
![types of analog to digital converter types of analog to digital converter](https://blog.degruyter.com/wp-content/uploads/2017/06/analog-computer-1.jpg)
And, as before, we won’t go into huge detail about how these ADCs work, but we will cover the basics. Like the DAC post, this one is introductory, so we won’t cover every analog to digital converter that exists rather I’ll discuss the most common ones in use today. Finally, ADCs are more complicated, but a good understanding of DACs can help you better understand how ADCs work. Second, a lot of the specs that apply to DACs also apply to analog to digital converters.
![types of analog to digital converter types of analog to digital converter](https://hardwarebee.com/wp-content/uploads/2019/06/An-Illustration-of-Digital-Representation-of-an-Analog-Signal.png)
First, some analog to digital converters use DACs as part of their makeup. I strongly advise you check it out before reading this article if you haven’t already. Like digital to analog converters or DACs, the analog to digital converter or ADC is everywhere.Ī while back, I published an article on DACs titled Digital to Analog Converters – An Introductory Tutorial.