lossless transmission line in tina-ti?

Joe Cahill

Other Parts Discussed in Thread: TINA-TI

Is it possible to simulate a lossless transmission line in TINA-TI v9? I don't have to have a schematic symbol for it, I'll be okay with importing text to instantiate it.

By the way, this simulator has become my go-to simulation tool because of its ease of use and the breadth of library.

Joe

over 11 years ago

0 John Miller - Sensing over 11 years ago

TI__Mastermind 34405 points

Joe,

We do not have any ready-made TINA models of lossless transmission lines.
The most likely way to do it is to create some subcircuit blocks with the idealized equations.

We have found that simulations using ideal lossless lumped components (L's and C's) struggle to converge until a small amount of loss is added.

Don't know if the lossless transmission lines will behave the same way, but it might be good to keep it in mind.

Please let me know if you have any questions.
Thank you for your interest in TINA-TI.

Regards,

John

0 Britt Brooks - Online Design Tools over 11 years ago in reply to John Miller - Sensing

TI__Mastermind 41310 points

Joe,

There are two models for transmission lines that I have used in TINA Industrial. Perhaps one of these will help you. Please take a look at the attached file.

Britt

5102.trans_line.TSC

0 Joe Cahill over 11 years ago in reply to Britt Brooks - Online Design Tools

Prodigy 30 points

Thanks Britt,

I am happily using the lossless model now. I have a little work to do to get my application of the rlgc model to behave as I expect but the lossless model is very much sufficient for what I am doing.

Thanks again!

0 Thomas Kot over 10 years ago in reply to Britt Brooks - Online Design Tools

TI__Prodigy 340 points

Britt,

I download the 5102.trans_5F00_line.TSC and open it in TINA-TI.

set the time delay to 5us and characteristic impedance to 100, then connect it to a voltage generator to give 1MHz sine wave and terminated with 1K.

to see the output of the transmission line, it always zero.

question is how to operate it in TINA-TI?

Regards,

Thomas

0 Britt Brooks - Online Design Tools over 10 years ago in reply to Thomas Kot

TI__Mastermind 41310 points

Thomas,

It appears to work for me. Perhaps your simulation time in the transient window was less than 5u. If that is the case, then you would not see anything at the output of the transmission line. Please see the attached example.

Britt

3125.trans_line_test.TSC

0 Joe Cahill over 10 years ago in reply to Thomas Kot

Prodigy 30 points

I've attached an application schematic that simulates.

Make only 1 change at a time (either to the schematic or to your simulation options and controls) until it stops working or you get to the schematic you want simulated.

Joe

scratch - FSI txb0304 driver effects - LPC AC terminations.TSC

0 Thomas Kot over 10 years ago in reply to Britt Brooks - Online Design Tools

TI__Prodigy 340 points

Thanks very much. It works now.

Thomas

0 Adam Jackson over 10 years ago in reply to Thomas Kot

Prodigy 80 points

Hi all,

0434.Model_Param_Error____Lossy_TX_Line.TSC

Has anyone had any luck with getting the lossy model working? All I can get is a cryptic "Model parameter error"

I've got sensical numbers entered for RLCG and E length...

Thanks,

Adam

0 Britt Brooks - Online Design Tools over 10 years ago in reply to Adam Jackson

TI__Mastermind 41310 points

Adam,

Let me check on this. I have not used the Lossy model yet.

Britt

0 Adam Jackson over 10 years ago in reply to Britt Brooks - Online Design Tools

Prodigy 80 points

Thanks Brit,

Well, I think I maybe found the issue, I found this note on spice for the LTRA model:

The types of lines implemented so far are : uniform transmission line with series loss only
(RLC), uniform RC line (RC), lossless transmission line (LC), and distributed series
resistance and parallel conductance only (RG). Any other combination will yield erroneous
results and should be avoided. The length (LEN) of the line must be specified.

I set G=0 and sure enough, no more parameter error. So it seems this can't really do RLCG, just RLC.

Please let me know if you find different.

Thanks!
Adam

0 Britt Brooks - Online Design Tools over 10 years ago in reply to Britt Brooks - Online Design Tools

TI__Mastermind 41310 points

Adam,

I believe that the Lossy transmission line only works with the following combinations of parameters:

LC, RLC, RC, and RG

In your example, if you set G to 0, the simulation will run.

Britt

0 Britt Brooks - Online Design Tools over 10 years ago in reply to Britt Brooks - Online Design Tools

TI__Mastermind 41310 points

Adam,

We must have been typing at the same time! You are very correct and DeisgnSoft has confirmed.

Britt

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lossless transmission line in tina-ti?