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The following figure shows the symbol of an OR gate, which is having two inputs A, B and one output, Y. For remaining combinations of inputs, the output, Y is ‘1’. If both inputs are ‘0’, then only the output, Y is ‘0’. Here A, B are the inputs and Y is the output of two input OR gate. The following table shows the truth table of 2-input OR gate. This logical OR is represented with the symbol ‘+’. OR gateĪn OR gate is a digital circuit that has two or more inputs and produces an output, which is the logical OR of all those inputs. That means, the output of AND gate will be ‘1’, when all the inputs are ‘1’. Similarly, if there are ‘n’ inputs, then the AND gate produces an output, which is the logical AND of all those inputs. This AND gate produces an output (Y), which is the logical AND of two inputs A, B. The following figure shows the symbol of an AND gate, which is having two inputs A, B and one output, Y.
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For remaining combinations of inputs, the output, Y is ‘0’. If both inputs are ‘1’, then only the output, Y is ‘1’. Here A, B are the inputs and Y is the output of two input AND gate. The following table shows the truth table of 2-input AND gate. It is optional to represent the Logical AND with the symbol ‘.’. AND gateĪn AND gate is a digital circuit that has two or more inputs and produces an output, which is the logical AND of all those inputs. So, we can implement these Boolean functions by using basic gates. In earlier chapters, we learnt that the Boolean functions can be represented either in sum of products form or in product of sums form based on the requirement. Now, let us discuss about the Logic gates come under each category one by one.
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We can classify these Logic gates into the following three categories. Hence, the Logic gates are the building blocks of any digital system. The basic digital electronic circuit that has one or more inputs and single output is known as Logic gate. Similarly, the range of voltages corresponding to Logic High is represented with ‘1’. The range of voltages corresponding to Logic Low is represented with ‘0’. Digital electronic circuits operate with voltages of two logic levelsnamely Logic Low and Logic High.