Use NAND gate to enable signal

Thread Starter

amfabian02320

Joined Jan 17, 2018
4
Hello! Would you please explain me how to use a NAND gate in order to enable a signal? With AND gate I have Enable and the Signal as inputs and I can control when the signal passes the gate, but how do I do that with a NAND gate? Thank you!
 

ElectricSpidey

Joined Dec 2, 2017
1,160
A NAND gate is the same as an AND gate, except the output is inverted.

So when all of the inputs are high the output goes low.

When any of the inputs go low, the output goes high.
 

ElectricSpidey

Joined Dec 2, 2017
1,160
Yes, you can probably tie several NAND gates together to get the action of an AND gate, but I have to go to work now, so I can't work it out right now.

Sorry
 

LesJones

Joined Jan 8, 2017
2,642
The NAND gate is probably part of a package containing 4 NAND gates. Just use one of the spare NAND gates as an inverter. Just connect both inputs of the spare NAND gate to the output of the one you are using. The function of the two NAND gates connrcted in that way will behave as an AND gate.

Les.
 

philba

Joined Aug 17, 2017
960
If you control the signal source, you can change the sense of it and use the inverted control signal to get the same value out. Just work it back to the source. Also, consider non inverting buffers with an output enable pin.

A circuit I built has a peripheral that needs a falling edge. I use an inverting buffer so my code creates a rising edge to the buffer to get the right signal to the device.

What's the specific problem you are trying to solve?
 

WBahn

Joined Mar 31, 2012
25,770
If you need a black box that behaves like a two input AND gate and all you have a NAND gates, the reflect on the fact that a NAND gate is, logically, an AND gate followed by a NOT gate and that a NOT gate followed by a NOT gate is just a buffer. So now ask how you might make a NOT gate out of a NAND gate.
 
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