What's the opposite of a NOT gate?

  • Thread starter Thread starter golmschenk
  • Start date Start date
  • Tags Tags
    Gate
Click For Summary
SUMMARY

The discussion centers on the need for a circuit component that acts as the opposite of a NOT gate, specifically a buffer that allows for current amplification without requiring the signal source to handle higher current levels. Participants suggest using two NOT gates in series, an AND gate with identical inputs, or dedicated buffer chips. An op-amp voltage follower is also recommended for applications requiring signal integrity over distance. The consensus is that buffers are essential for driving higher loads without altering the logical state of the signal.

PREREQUISITES
  • Understanding of digital logic gates, specifically NOT and AND gates.
  • Familiarity with buffer circuits and their functionality.
  • Knowledge of operational amplifiers, particularly voltage followers.
  • Basic concepts of signal integrity and current amplification in electronic circuits.
NEXT STEPS
  • Research dedicated buffer chips and their specifications for various applications.
  • Learn about operational amplifier configurations, focusing on voltage followers.
  • Explore the use of combinational logic gates in creating custom buffer circuits.
  • Investigate the impact of rise and fall times in signal transmission over long distances.
USEFUL FOR

Electronics engineers, hobbyists designing circuits, and anyone interested in optimizing signal integrity and current handling in electronic designs.

golmschenk
Messages
35
Reaction score
0
I essentially need the opposite of a NOT gate. I know that sounds silly, but what I'm really looking for is something that will provide the current based on the signal sent to it so that the more sensitive circuitry sending the signal doesn't have to run higher current levels. I've found I could do this using two NOT gates in a row or an AND gate and just using both the inputs on the AND gate to be the same, but I'm guessing there must be a circuit piece already built for this. One that I can provide a signal and supply voltage to and it will provide the output current. For what I'm doing the signal voltage and supply voltage need not be the same. I just need to make sure the circuitry sending the signal doesn't have to send the higher current with the signal itself. Thanks!
 
Engineering news on Phys.org
What you are describing is called a http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/buffer.html" .
 
Last edited by a moderator:
Are you looking for a relay?

Edit: Jambaugh looks more capable at this, I'd look at his suggestion first :)[/size]
 
OK, so you want a buffer.

Using two NOT gates, or an AND gate, or some other form of buffer made from whatever logic gate chips you have available should be fine.

Alternatively, maybe use an opamp voltage follower? Or investigate buying dedicated buffer chips.
 
A buffer is made of 2 inverters internally. If you need to drive a long distance and need 2 (or any even number) buffers, using a series of even number of inverters is a better solution.

If you don't care about the difference in rise time and fall time, you can use pretty much any combinational logic gate to make it a buffer.
 
Last edited:
Awesome. Thanks for the help!
 
So the natural progression is "AND, OR, NAND, NOR, NOT, BUFFER"? Sorry, but that just doesn't sound right to me (linguistically). Let me do some research.
 
Also called a follower.
 
mhearne said:
So the natural progression is "AND, OR, NAND, NOR, NOT, BUFFER"? Sorry, but that just doesn't sound right to me (linguistically). Let me do some research.
What "progression"?

Buffers aren't really considered a logic function, since they don't really do anything to the signal, logically speaking. They just help it drive higher loads.
 

Similar threads

Replies
12
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
4K
Replies
2
Views
2K
  • · Replies 42 ·
2
Replies
42
Views
5K
Replies
6
Views
5K
Replies
55
Views
6K
  • · Replies 25 ·
Replies
25
Views
3K
  • · Replies 5 ·
Replies
5
Views
1K
Replies
13
Views
3K