# Easy pulse generator

#### electronicbasickid

Apr 15, 2021
10
Hi,

I am trying to make a short pulse generator from any pulse input. By this I mean I want a final output with a fixed pulse width no matter what input I have.
I tried to do it with a not gate linked to a and gate. It did work but apparently the solution can be based on ONE component only.

Any ideas?

Last edited:

#### Externet

Aug 24, 2009
869
Trying to understand you; a single component only being a capacitor; will pass a short pulse from many pulse width inputs. It is called a differentiator.

Any widht pulse >-----------------------||------------------------> a 'short' pulse out >---------/\----------

#### electronicbasickid

Apr 15, 2021
10
Yes, thank you for your answer ! I tried this solution but I have to use logic gates.

#### bertus

Moderator
Nov 8, 2019
2,858
Hello,

Is this homework?

Bertus

Apr 15, 2021
10

#### bertus

Moderator
Nov 8, 2019
2,858
Hello,

How about a RC circuit with a schmitt trigger gate.

Bertus

#### electronicbasickid

Apr 15, 2021
10
Hello,

How about a RC circuit with a schmitt trigger gate.

Bertus

I actually found this on the internet but my teacher said it was supposed to be a single component and most likely a single logic gate.
I will add this to my researches. Thank you!

#### AnalogKid

Jun 10, 2015
2,701
A single *logic* component, like one inverter or one two-input gate, sure. But any pulse forming circuit will need some kind of delay element or group of components to set the output pulse width. This can be as simple as one resistor and cone capacitor, as shown, or even a string of gates with no R's and C's, but there has to be something that determines when the end of the output pulse is.

Does the problem come with an output pulse width range?

ak

#### crutschow

May 7, 2021
586
Do you need the circuit to operate whether the input pulse is both shorter or longer than the desired output pulse?

#### electronicbasickid

Apr 15, 2021
10
A single *logic* component, like one inverter or one two-input gate, sure. But any pulse forming circuit will need some kind of delay element or group of components to set the output pulse width. This can be as simple as one resistor and cone capacitor, as shown, or even a string of gates with no R's and C's, but there has to be something that determines when the end of the output pulse is.

Does the problem come with an output pulse width range?

ak

Yes it does, it has to be around 1-100ns.

#### electronicbasickid

Apr 15, 2021
10
Do you need the circuit to operate whether the input pulse is both shorter or longer than the desired output pulse?
Yes exactly.

#### Harald Kapp

##### Moderator
Moderator
Nov 17, 2011
13,102
my teacher said it was supposed to be a single component and most likely a single logic gate.
Can you show us the complete task description? I don't know any single logic gate thjat requires no external components to fulfill this task. As others mentioned before you'll have to add some passive components (R, C) to generate a specific timing.
A monostable multivibrator comes to mind, still requiring R+C for the timing.

#### Kabelsalat

Jul 5, 2011
178
If you already have an oscillator producing square waves, then short pulses can easily be achieved by using one AND-gate where one input are connected to a RC circuit.
I think there is one of those that TTL chips have schmitt-trigger inputs, but doesn't remember it's number.

#### WHONOES

May 20, 2017
1,215
I seem to remeber doing something like this many years ago using an Exor gate a diode a resistor and a capacitor.

#### AnalogKid

Jun 10, 2015
2,701
I seem to remeber doing something like this many years ago using an Exor gate a diode a resistor and a capacitor.
Usually, an XOR gate with an R-C time delay is used to produce an output pulse for both the leading and trailing edges of the input pulse. What the TS wants sounds like a simple monostable that is triggered by the leading edge only.

ak

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