The term “Digital Electronics” is made up of two broad sub terms .One is Digital and other is Electronics. Let me take the term electronics first. If we observe our day to day life by one or the other mean we use electronics in our use. For example you get up in the morning by hiring some sound from the alarm .This alarm is nothing but one electronic gadget . Similarly you use television , computer , watch , camera and so on .All this gadgets are electronic in technical terms electronics means the branch of science which deals with controlled flow of electrons to perform some operations.
Now comes the term digital. Digital word comes from the same source as the word digit. Digit means something which is countable. Digital means the thing which deals with numbers. Now if we combine the both terms digital and electronic the birth of the new term comes that is digital electronics. So in simple language the term digital electronic means controlling the flow of the electrons by means of some number logic.
In the world of digital electronics, to control the flow of electrons means nothing but either to allow them to pass or not .This is similar to the switch. If switch is ON then current which is the flow of electrons will pass and if switch is OFF then current will not pass. In digital electronics this ON state of the switch is termed as ‘1’ and OFF state of the switch is termed as ‘0’. Also some times in digital electronics the term ‘1’ is referred as TRUE logic and ‘0’ as ‘FALSE’ logic. This is shown in figure below.
It is now clear that digital electronics deals with only two discrete values either high or ‘1’ or low ‘0’ .So that some time this digital electronic system is called as discrete value discrete time system. And by using this 1 or 0 logic many number systems are developed such as binary, octal , decimal , hexadecimal etc. This number systems are used to control various operation of the system and term digital electronics arises.
Now the question arises that why we need this digital technique to control the operations of the system and why conventional electronics that is analog electronics can’t be used in some operations. So the advantages of the digital electronics are as follows:
Advantages digital electronics
- Noise Reduction: The term noise means any unwanted signal which is in the information signal and which distort the original information signal. In analog signal each value of the signal affects the system Since in digital electronics there are only two logic level or voltage level even though the noise is added to the signal it will not affect the digital signal .
- Portability: Since the digital electronics deals with digital data ,which can be stored in the memory. So it is very portable.
- Flexibility: Any system built using digital electronics can perform differently by simply changing the digital code which is nothing but the digital logic . So for minor change in the system performance we need not to change the whole hardware of the system.
- Accuracy and Precision: In digital system any system data is represented by numbers .This numbers are stored in memory. Since now ample of memory is available at very low cost we can represent the system data by numbers with long precision .Since the effect of environmental changes is less in digital electronic system it gives very accurate result.
Here we discussed the major advantages of the digital electronics system .We know that each coin has two sides .So there are also some disadvantages of digital electronic system.
Disadvantages digital electronics
Quantization Error:
We know that the real world signals like temperature, pressure, flow, voice etc. are all analog signals. But if we want to convert them into digital signal we require sampling of the analog signal. This sampling means to sample the analog signal at particular time interval. This sampled signal is assigned some predefined value of voltage and this process is called as quantization. Since the assigned value is the combination of the predefined values they will surely differ from the actual value of the sampled signal. This difference of the actual and quantized signal is called as quantization error.
Time Delay For Critical Real Time System:
As I have already discussed that most of the signal are analog in nature and to control the system by means of digital we have to first convert it into digital and after processing in digital domain we have to convert it back into analog domain .So in this conversion process considerable time is consumed .For this reason it is very rarely used in real time system in which system response should be achieved as soon as the input comes to the system.
