Buffer Gate
A	Q
0	0
1	1

A buffer, is a basic logic gate that passes its input, unchanged, to its output. It's behavior is the opposite of a NOT gate. The main purpose of a buffer is to simply amplify a weak signal.

A buffer has one input and one output. The output of a buffer always equals its input.

Standard symbol

Below are the three standard symbols that represent the OR gate:

ANSI	IEC	DIN

CMOS Implementation

A CMOS buffer gate with one input and one output can be realized as simply two inverters back to back - built out of just 4 gates.

The table on the right shows the states of the four transistors with the various inputs of A.

Buffer Gate by Transistor
A	Q1	Q2	Q3	Q4	Q
0	1	0	0	1	0
1	0	1	1	0	1

7407: Hex Buffer/Driver

The 7407 is a TTL chip with 14 pins. Two pins are used for V_DD and GND, the other 12 pins are used for the 6 independent buffers. The 7407 chip implements the following expressions:

4050 cmos Hex Buffer/Driver

The 4050 is a CMOS Hex Buffer with 16 pins. Two pins are used for V_DD and GND, 12 pins are used for the 6 independent buffers. Pins 13 and 16 are not connected.