## Logic Gates-

Before you go through this article, make sure that you have gone through the previous article on Logic Gates.

We have discussed-

• Logic gates are the basic building blocks of any digital circuit.
• Logic gates are classified as-

## Alternative Logic Gates-

 Alternative logic gate is an alternate logic gate that produces the same output as the original logic gateand can be used during the unavailability of the original logic gate to serve the same purpose.

Alternative logic gates are also called as Alternate Gates.

Alternative logic gates are also called as Bubbled Gates since they contain bubbles in them.

The following table shows the original logic gate and its corresponding alternate gate-

## Rules To Memorize Alternative Logic Gates-

The following rules are helpful in drawing an alternate logic gate for a given logic gate-

#### For AND, NAND, OR & NOR Gates-

• Both the inputs of alternative gate will have bubbles (which represents NOT gate).
• For AND structured original gate, alternative gate will be OR structured.
• For OR structured original gate, alternative gate will be AND structured.
• If bubble is present at the output of original gate, then no bubble will be present at the output of alternative gate.
• If bubble is not present at the output of original gate, then a bubble will be present at the output of alternative gate.

#### For EX-OR & EX-NOR Gates-

• One of the inputs of alternative gate will have a bubble (which represents NOT gate).
• For EX-OR structured original gate, alternative gate will be EX-NOR structured.
• For EX-NOR structured original gate, alternative gate will be EX-OR structured.
• If bubble is present at the output of original gate, then no bubble will be present at the output of alternative gate.
• If bubble is not present at the output of original gate, then a bubble will be present at the output of alternative gate.

To gain better understanding about Alternative Logic Gates,

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