A digital buffer (or a voltage buffer) is an electronic circuit element that is used to isolate the input from the output, providing either no voltage or a voltage that is same as the input voltage. It draws very little current and will not disturb the original circuit. It is also called as unity gain buffer or a because it provides a gain of 1, which means it provides at most the same voltage as the input voltage, serving no amplification function.
![Image result for buffer in vlsi](http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/ietron/buf.gif)
Usage of buffer in Physical Design
1. Setup Violation fixes
2. Hold Violation fixes
3. Max Trans Violation Fixes
4. xtalk reduction
![Image result for buffer in vlsi](http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/ietron/buf.gif)
Usage of buffer in Physical Design
1. Setup Violation fixes
2. Hold Violation fixes
3. Max Trans Violation Fixes
4. xtalk reduction