Editing buffer gate

{{title|Buffer Gate}}{{logic gate
|title = Buffer Gate
|name = buffer
}}
A '''buffer''', is a basic [[logic gate]] that passes its input, unchanged, to its output. Its behavior is the opposite of a [[NOT gate]]. The main purpose of a buffer is to regenerate the input, usually using a strong high and a strong low. A buffer has one input and one output; its output always equals its input. Buffers are also used to increase the propagation delay of circuits by driving the large capacitive loads.

== Description ==
{{expand section}}
A buffer is a very basic active device that generates an output identical to its input. In most technologies, a buffer is made of two [[inverter]]s back-to-back. One of the many purposes for a buffer is to regenerate weak output from [[non-restoring logic]].

==Design==
{{empty section}}

== Symbolic representation ==
Buffers are typically drawn on schematics using one of a standard symbol. Below are three of the commonly found standard symbols.
{| class="wikitable"
|-
! ANSI !! IEC !! DIN !! British
|-
| [[File:buffer gate (ansi).svg|100px]] || [[File:buffer gate (iec).svg|100px]] || [[File:buffer gate (din).svg|100px]] || [[File:buffer gate (british).svg|100px]]
|}

==Implementations==
A buffer can be implemented in variety of of technologies.

=== CMOS ===
A CMOS buffer gate with one input and one output can be realized as simply two [[inverter]]s 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.
{| class="wikitable" style="float: right;"
|-
! colspan="6" | Buffer Gate by Transistor
|-
! A !! Q<sub>1</sub> !! Q<sub>2</sub> !! Q<sub>3</sub> !! Q<sub>4</sub> !! Q
|-
| 0 || 1 || 0 || 0 || 1 || 0
|-
| 1 || 0 || 1 || 1 || 0 || 1
|}
[[File:Buffer gate cmos.png|200px]]
{{clear}}
== Discrete Chips ==
Various buffers/drivers exist chips as well for both [[7400 series]] and [[4000 series]].

=== [[7400 series]] chips ===
{{empty section}}

=== [[4000 series]] chips ===
{{empty section}}

The 7407 is a TTL chip with 14 pins. Two pins are used for V<sub>DD</sub> and GND, the other 12 pins are used for the 6 independent buffers. The 4050 is a CMOS Hex Buffer with 16 pins. Two pins are used for V<sub>DD</sub> and GND, 12 pins are used for the 6 independent buffers. Pins 13 and 16 are not connected. Both chips implement the expression Q<sub>N</sub> = A<sub>N</sub>

<gallery>
File:7407.svg|7407 Hex Buffer/Driver
File:4050.svg|4050 CMOS Hex Buffer/Driver
</gallery>


[[Category:logic gates]]
@@ Line 47: / Line 47: @@
 === [[4000 series]] chips ===
--CD4050 NonInverting 6 Channel (THE Jellybean go-to part for many people. This is often used as a 5 volt to 3.3 volt, voltage level shifter in hobby electronics for displays and sensors)
+{{empty section}}
--CD4049 Inverting version of the CD4050.
--HEF40244 NonInverting 8 channel with 2 independently selected (4 channels each) tristate enable lines. This IC also has the advantage of inputs and outputs on opposing sides of the chip pin for pin.
 The 7407 is a TTL chip with 14 pins. Two pins are used for V<sub>DD</sub> and GND, the other 12 pins are used for the 6 independent buffers. The 4050 is a CMOS Hex Buffer with 16 pins. Two pins are used for V<sub>DD</sub> and GND, 12 pins are used for the 6 independent buffers. Pins 13 and 16 are not connected. Both chips implement the expression Q<sub>N</sub> = A<sub>N</sub>