Analog-to-digital converters are used in most modern consumer electronics and many commercial applications. Whenever you need to convert real-world inputs into a digital signal for computer storage, manipulation, or other applications, you use an ADC. There are many different types of ADCs available. You can read Microelectronics news to now more on this particular subject. Choosing the right ADC depends primarily on your actual needs.
What to consider?
To choose the right ADC, you must first consider four critical factors, such as resolution, speed, accuracy, and noise. Once you have assessed the project needs in these areas, you can further narrow your selection by considering less important variables, such as input voltage, interface, and number of channels.
ADC selection criteria to consider
It can be helpful to point out how resolution, speed, accuracy and noise affect your choice.
Resolution: Refers to the number of output bits the ADC can generate for each conversion. This value determines the smallest input signal the system can represent. Resolution also defines the smallest incremental variation of the analog signal that the ADC can express.
Speed: Does it have to do with the sampling rate of the device? What is the greatest number of conversions per second that the ADC can handle? The sampling rate is determined by the time it takes to perform a single conversion.
Accuracy: It is relatively simple. To what extent does the output correspond to the input? How much of the output is the desired signal? In general, we evaluate the accuracy in terms of noise present in the output signal, using a measurement called the signal-to-noise ratio, where a higher value is better. Even in an ideal ADC, some amount of noise will be present as rounding must necessarily occur to digitize an analog signal.
Quantization noise: This is one of several types of noise that contribute to the accuracy of the device. This type of noise deserves a separate mention because quantization noise is unavoidable in analog/digital conversion. Simply put, when a continuous set converts to a discrete set, we can expect to lose some information. With a sufficiently high resolution, quantization noise can be overcome functionally.
Overview of common ADC architectures
ADC’s various projects have their own strengths and weaknesses. As a result, the design and intended use case will largely determine the type of ADC you choose to use. A clear idea of what you want to achieve from the device will help you prioritize the four factors described above and guide you towards the right type of ADC architecture. The most common ADC architectures are Flash, Successive approximation, Delta-sigma, and A pipeline.
Pipeline ADCs represent a somewhat unique method. They combine some of the best qualities of SAR and flash ADCs, managing to achieve both high speed and high resolution. Although flash ADCs are large and expensive, their speed ensures the highest quality analog to digital video recording conversion. SARs are very popular in data acquisition and instrumentation applications. The delta-sigma architecture can boast astounding accuracy, but it is also the slowest of the most popular designs. Pipelined ADCs are becoming increasingly popular due to their ability to combine both reasonably high resolution and speed.