E-Management (Apr 2021)
Digitization of analog signals
Abstract
We live in the world of digital technologies – everyone has a digital phone, television has switched to a digital broadcasting format as it is more noise-immune, digital processes are literally in every household appliance, from the iron to the computer on which this article was written. Digital technologies simplify our lives, some operations performed by humans require large material costs, for example, writing text on a typewriter and computer vary greatly. The gain of the computer is especially evident when editing the test. They brought us comfort – how nice it is when the processor that monitors the temperature in the house increased the heat supply during a cold snap or reduced it in order to save money in the absence of people in the house.But in order for the digital system to perform this or that action, it needs a command coming from the sensor. It can be a temperature, humidity, pressure sensor. Or maybe a microphone used in voice control systems. All these sensors, without which the operation of a digital system is impossible, give an analog signal that changes its value over time. The digital system is not sensitive to such a signal. It “does not understand” the signal. The problem is solved by ADC (analog-to-digital converters). They have a different structure, varying degrees of complexity, the device, depending on the parameters of the digitized signal. For example, the temperature in the house changes very slowly, even when warming up or when the heating is turned off in frost, the temperature rises or, accordingly, does not fall faster than one degree per hour. The ADC speed requirements for the temperature sensor are very low. Instead, a microphone is used to receive voice commands. In order to distinguish the voices of people and to carry out the commands of some people and not to carry out commands from others, processing of the signal spectrum with a width of kilohertz is required - which means that the signal level will change at a frequency of thousands of times per second. This is a very high demand. The different types of ADCs, their design and application will be discussed in this article.
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