Digital phase shifter

mik3

Joined Feb 4, 2008
4,843
A simple phase shifter can be made with a NOT gate due to its propagation delay. The more gates you add in series the more the phase shift.
 

mik3

Joined Feb 4, 2008
4,843
Connect two NOT gates in series (the output of the first in the input of the second). Then connect you signal on the input of the first. You will get a delay of about 50ns to see the signal on the output of the second gate.
 

mik3

Joined Feb 4, 2008
4,843
180 is easily implemented with a NOT gate. To achieve other phase shifts with a delay you have to know the signal's frequency and calculate the appropriate delay otherwise you need more complex circuits which read the signal and perform the required delay.
 

mik3

Joined Feb 4, 2008
4,843
And you want to phase shift one signal as to vary the duty cycle?

But why you need such high frequencies?
 

Thread Starter

DominusDRR

Joined May 25, 2009
26
Yes. I want to phase shift the duty cycle in 90 ° and add the two signals (input and output) to increase the duty cycle time.
 

mik3

Joined Feb 4, 2008
4,843
Why don't you use a triangular wave, a comparator and a pot to generate PWM from 0% to 100%.

Feed the triangular wave on one input of the comparator and the output voltage of the pot to the other.
 
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