Digital electronics is a branch of electronics technology that deals with information in digital form. It generates, stores, and processes data in positive and negative states. The positive state is represented by the number 1 and the negative state by the number 0. Thus, data transmitted or stored in digital form is expressed as a string of 0’s and 1’s.

Examples of Digital Electronics 

A few examples are:

Digital computers, calculators, digital video and audio equipment, information appliances, digital cameras, digital televisions, memory, CD-ROMs, mobile phones, VLSI, and chip designing.

Advantages 

  • Digital systems make data storing easy.
  • Digital systems are generally easy to design.
  • The accuracy and precision of digital systems are greater than that of analogue systems.
  • This system is less affected by noise.

Applications

  • Entertainment and communication such as telephony and telegraphy.
  • Defence applications such as RADAR and Anti-craft guns.
  • Industrial applications like automatic door openers, power systems, and safety devices.
  • Medical services such as X-rays and ECGs.
  • Instrumentation such as CRO, frequency counters, signal generators and strain gauges.

Logic Gates

A logic gate is a digital circuit that can be implemented based on some logic or conditions. It is the basic building block of a digital circuit. Logic Gates have one output corresponding to two inputs. These two inputs are LOW (0) or HIGH (1), respectively, represented by different voltage levels. The low state is approximately zero volts (0 V), while the high state is approximately positive five volts (+5 V). Logic gates like AND, OR, NOT are called basic gates, and NAND, NOR, X-OR, and X-NOR gates are called universal gates because these gates can be implemented by using basic gates. 

Logic expression: If the input variables are A and B and the output variable is Y, then the logic expression for the particular gate. 

Truth Table: A truth table is a table that represents all the possible values of logical variables or statements and all the possible results of the given combinations of values. 

Boolean algebra is a Boolean expression for a particular gate, such as inputs and outputs.

Now we will learn about logic gates in detail.

  • AND GATE: The AND gate is defined as output as (1) one if and only if all the inputs are (1) one. 7408 is the two Inputs AND gate IC. A and B act as the input terminals and Y is the output terminal.
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  • OR GATE: The OR gate is defined as the output as (1) one if one or more than 0 inputs are (1) one. 7432 is the two Input OR gate IC. A and is the input terminal and Y is the output terminal. 

Logic symbol:

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  • NOT GATE: The NOT gate is also known as an inverter. It has one input (A) and one output (Y). IC No. is 7404. Its logical equation is, 

Logic symbol:

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  • NAND GATE: The IC no. for the NAND gate is 7400. The NOT-AND operation is known as the NAND operation. If all inputs are 1 then the output produced is 0. NAND gate is inverted AND gate.
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  • NOR GATE: The NOR gate has two or more input signals and only one output signal. IC 7402 is two I/P IC. The NOT-OR operation is known as the NOR operation. When all the inputs are 0 then the O/P is 1. NOR gate is an inverted OR gate.
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  • EX-OR GATE: The EX-OR gate can have two or more inputs but produce one output. 7486 is two inputs IC. It produced high output when inputs have alternate values
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  • EX-NOR GATE: EXCLUSIVE-NOR (commonly written as XNOR) is the NOT of XOR gate. i.e. the logic gate obtained by complementing the output of an XOR gate.  
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Applications of Logic Gates

  • NAND Gates are used in adders, decoders, Multiplexers.
  • They are used in circuits involving computation and processing.
  • They are also used in security systems.
  • They are used in the functioning of safety devices.
  • NOT gate is used as an inverter.

Conclusion

This article explains the basics of digital electronics and logic gates. Digital electronics is a branch of electronics technology that deals with information in digital form. It generates, stores, and processes data in positive and negative states. A logic gate is a digital circuit that can be implemented based on some logic or conditions. Logic gates like AND, OR, NOT are called basic gates, and NAND, NOR, X-OR, and X-NOR gates are called universal gates