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What is the role of a comparator?

Latest Updated:10/01/2006

Question:

What is the role of a comparator?

Answer:

Analog variables that continuously change, such as temperature, humidity, sound, and light, fill our environment. However, many of the systems we use perform digital processing. To interface between an analog signal and a digital circuit (in a system), therefore, a comparator is used.
In other words, a comparator has the function of comparing the signal used as a reference and the input analog signal, and based on the comparison result, changing the output to "0" or "1".
An example may be judging whether or not the temperature has exceeded a specific temperature (reference temperature). In this case, the comparator compares the temperature at some point in time with the specific temperature (actually, the comparison is done after both temperatures have been converted into voltage values), and the comparison result is output as a digital value (for example, "0" if the temperature is below the specific temperature, and "1" if it is equal to or exceeds it). Digital signal processing is done within the device based on these two values.



In addition to the comparator, an operational amplifier is used to perform processing on analog signals. For the role of an operational amplifier, refer to Operational Amplifier Basics.
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Comparators