How to generate a short pulse from a longer pulse

Thread Starter

kintaro

Joined Jun 1, 2022
16
I have a pulse of 10 nesc wide. (low 0V, high 1V)
How do I build a circuit that take this 10 nsec pulse and output a pulse much smaller (<1 nsec)?
The rise point of the 10 nsec pulse and the <1 nsec pulse should be almost the same (<1 nsec difference)
any ideas?
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crutschow

Joined Mar 14, 2008
31,087
Generating a 1ns pulse would require a very fast circuit with sub ns rise and fall times.
Don't know of any commercial digital circuits that can do that.
What will this 1ns pulse do?
 

ronsimpson

Joined Oct 7, 2019
2,515
ECL logic gates like this one respond in 300pS and a signal is in the 1V range.
There needs to be more thinking about this, but here is a start.
Input signal to pin-2. Use a RC to get the edges of the signal. (RC) feed that to pin-3.
The output will be 300pS behind the input and will pulse for a time set by RC.
There is a better way but I don't have time now. I have used XOR gates to do something like this.
I have used 3 gates delay to make the 1nS delay that is needed. (no RC)
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ronsimpson

Joined Oct 7, 2019
2,515
You can use logic device propagation delays to generate sub-ns short pulses.
Thank you, the last circuit is the one I wanted to see.
Most logic cannot do sub nS. It is hard to find logic that can do 2nS. The ECL type are very fast and have 1-volt signals. (requirement)

We don't know enough yet. The signal is probably analog not digital. We don't know impedance. Too many unknowns.
 
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