delay line absolutly not working

Thread Starter

yef smith

Joined Aug 2, 2020
808
Hello, I am trying to build a delay line as shown below.
but as you can see in the schematics i get absolutely no delay from the input.
befaroe the delay line and after are the same .
Why i cant see any delay?

LTSPICE files are attached.

Thanks.
1712431932355.png
 

Attachments

ronsimpson

Joined Oct 7, 2019
3,144
I am certain you posted this days ago and were told U1 was not set up correctly. So I removed U1 and have V1 driving the delay line.

I will avoid that, and move to other problems. C1,2,3,4, R1, D1 are not connected to ground! You can't just leave them handing.

Next C1 is doing nothing. Move C1 to across R1. I did not do that but you need to.
1712434764200.png
Note I added a second ground at C2.
 

eetech00

Joined Jun 8, 2013
4,006
I am certain you posted this days ago and were told U1 was not set up correctly. So I removed U1 and have V1 driving the delay line.

I will avoid that, and move to other problems. C1,2,3,4, R1, D1 are not connected to ground! You can't just leave them handing.

Next C1 is doing nothing. Move C1 to across R1. I did not do that but you need to.
View attachment 319294
Note I added a second ground at C2.
You need to change the DC voltage source value to 3.0 since this is supposed to be a 3.0v circuit.
 

Thread Starter

yef smith

Joined Aug 2, 2020
808
Hello Alec,I almost cant see any delay.
As you can see below i did 3 sections and 6 sections but in both cases cant see any shift in the output .
Why i cant see any shift in the output?
Thanks.


1712484960512.png
1712484808031.png
 

ronsimpson

Joined Oct 7, 2019
3,144
Why i cant see any shift in the output?
Because the ground symbol did not connect to the wire. Please retry. There needs to be a connection dot where ground connects. Best to move Ground down a little and have a wire going up.
1712490829056.png
Again, C1 has no function. Important
Again, there needs to be a capacitor across R1 2k. Not critical
 

Thread Starter

yef smith

Joined Aug 2, 2020
808
Hello Alec , thank you for the advice , but I can’t see the what is the problem with the GND.
Could you please post and example of a delay line like I did so I could see the difference ?
 

Thread Starter

yef smith

Joined Aug 2, 2020
808
Hello, I tried to do a delay line for 500n long and 2n rise and fall timeas shown bellow.
but its almos not delaying the line although i have 6 sections.
Why its not delaying the pulse?
Thanks.

1712512481148.png
 

Alec_t

Joined Sep 17, 2013
14,377
Increase the L and/or C parameter. The nice thing about sims is that you can tinker with any variable to your heart's content without destroying real components :).
 

Thread Starter

yef smith

Joined Aug 2, 2020
808
Hello, I am just trying to create delay line for a pulse of tpw 500 ns, trf 10 ns. and use 6 LC section for delay(as much as possible)
how do i define the source and load of my simulation given the 74ABT04D generator and UCC5304DWVR reciever?
hex invertor soure data sheet and gate driver which recieves the delayed pulse (in hope it will bu good enough to generate a clean pulse on the output of the gate driver)

I know that an important part of the design is knowing what is the source and the load of thedelay line.
How do i define the source and load in my simulation given that the source is 74ABT04D and load is the input of UCC5304DWVR?
Thanks.


74ABT04D
https://www.mouser.co.il/datasheet/2/916/74ABT04-1541721.pdf

UCC5304DWVR
https://www.ti.com/lit/ds/symlink/ucc5304.pdf?ts=1715110966506
 
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