Manuel,

Thank you for your reply.  The simple test circuit is not working in LTSpice either.  Unfortunately I do not have Pspice and it is not free.  So maybe TINA-TI is my best option right now.

I also downloaded your TINA-TI model SLLM322.TSC for this part.  That model is working.  However, is it possible to edit the transformer parameters?  (I'm not seeing any way to do that and it's telling me the macro is encrypted.)

Or is there a way in TINA-TI to build my transformer that is center-tapped on both sides?  In TINA-TI's transformer options on the top toolbar, I'm only seeing an option to add a transformer that is center-tapped on one side.

Thanks,

Kevin

Hi Kevin,

You're welcome! TI does offer a free version of PSpice, found here, and I do recommend using that software moving forward.

Unfortunately, the transformer is the trickiest part of SN6505 simulations because the parameters in both TINA-TI and PSpice for TI designs are locked, as you mentioned, and there is not an ability to create center-tapped push-pull transformers.

Our recommendation is to import simulation models of the transformer part number you are interested in using. These can be requested from transformer vendors directly, and might also be compatible with 3rd party Spice programs.

Which parameters are you looking to evaluate in SN6505B systems?


Thank you,
Manuel Chavez

Manuel,

Thanks for your reply.  I'm just looking to verify correct behavior of my circuit and to make sure all components are rated sufficiently.

I requested a PSpice for TI license and I'm awaiting approval.  Overall, between TINA-TI and PSpice for TI, which one do you recommend?

In LTSpice, it is possible to model a center-tapped transformer on both sides by declaring SPICE for mutual inductance between any number of inductors as described in:

http://web.cecs.pdx.edu/~tymerski/ece222/How%20to%20create%20a%20transformer%20using%20LTSpice.pdf

Is any similar feature possible in PSpice for TI or TINA-TI for modelling dual center-tapped transformers?

Thanks,

Kevin

Manuel,

I'm trying to do what you suggested and import the simulation model from the transformer I'm using (Wurth Electronics 760390014).  The SPICE file for this transformer is located here:

https://www.we-online.com/web/en/electronic_components/produkte_pb/bauteilebibliotheken/ltspice/ltspice.php

However, when I go to import the .lib file into TINA-TI, I get the following error: "Error loading library. File is Empty!"

The .lib is encrypted, but it works fine to import into LTSpice.  However, I can't import it into TINA-TI.

How I can simulate a simple circuit with TI transformer driver SN6505B and Wurth Electronics 760390014 transformer?  

Thanks,

Kevin

Thanks,

Kevin

Hi Kevin,

Thank you for following up! PSpice for TI is TI's newest simulation software, so we are looking to make this the go-to choice for our customers and development efforts over TINA-TI. There is an ability to couple components in PSpice for TI (Place menu > PSpice Component... > Passives > Coupling), although I'm not familiar with coupling inductors for this purpose.

The error message observed from using the 760390014 model is likely from the model being encrypted and compatible with LTSpice only. This model will need to be an unencrypted version to be compatible with PSpice for TI, so I will check for unencrypted model to share with you; meanwhile, I do appreciate your patience.

Regarding the components in your simulation screenshot, the 1N914 diode is rated for 300mA max forward current. This won't be a problem if your isolated loads will be much smaller, but I do encourage you to use Schottky diodes recommended in the SN6505 datasheet like MBR0530 or RB168MM-40. Transformer 760390014 is a commonly-used transformer with our transformer-driver parts, and it is compatible with SN6505B.

I will follow up within 1 - 2 days regarding the transformer model, and please let me know if you have additional questions meanwhile.


Thank you,
Manuel Chavez

Hi Kevin,

I confirmed with Wurth: they do not have PSpice or unencrypted simulation models available for their parts. Other transformer vendors may have these models, but it may be most fruitful to analyze an SN6505B EVM in your lab setup. If you'd like, we can arrange delivery of an EVM via email or PM.


Best,
Manuel Chavez

Manual,

While I'm not able to import the transformer model into TINA-TI, I am able to import their encrypted model into LTSpice.  Will I be able to import an encrypted model into PSpice for TI?

I submitted the request for PSpice for TI on Friday after your reply, but I still have not received authorization for PSpice for TI.  How long does that typically take?

Thanks,

Kevin

Hi Kevin,

I understand the Wurth transformer models are designed for LTSpice, so problems aren't expected when importing the transformer model into LTSpice. Unfortunately, this model is encrypted, so it will not be compatible with PSpice for TI as these programs handle certain model files differently.

Regarding the PSpice for TI download approval, this can take 24-48 business hours, so it's possible you do have an approval email in your junk email folder or you may already be able to visit the PSpice for TI download website and access the download files. Otherwise, I expect the approval email to be sent by tomorrow morning at the latest.


Thank you,
Manuel Chavez

Manuel,

Could you please clarify what EVM is?

Also, I still have not gotten approval to download Pspice for TI

Thanks,

Kevin

Hi Kevin,

Thanks for letting me know -- I'll check on this with our PSpice team.

An EVM is a device evaluation board, a PCB meant to ease analysis of TI's devices under different settings. The SN6505B EVM can be found here.


Respectfully,
Manuel Chavez

Manuel,

I don't think an evaluation board is necessary as I've already used the SN6505B for other applications.  

I still haven't gotten approval for PSpice for TI.  Have you heard anything back from your PSpice team?  I would really like to try out PSpice for TI.

Thanks,

Kevin

Hi Kevin,

I understand, please do let me know if anything changes and you would like an evaluation board -- for this project or a future one.

Please verify that you've checked your Junk email folder, and please also check for an email that might be from Cadence. Our PSpice for TI team is looking into your access key email; I expect to follow up on this later today or by Wednesday. My apologies for the delay.


Thank you,
Manuel Chavez

Manuel,

I checked my Junk e-mail folder and I do not have any messages there.  I also don't see any e-mail from Cadence.  Let me know if I should submit another request for Pspice for TI using the link you provided earlier.

Thanks,

Kevin

Hi Kevin,

TI customer support notified me they do not have an order number for your PSpice for TI request, so it's possible they did not receive it. Please submit a new request for the software here, ensuring you are logged into this same myTI account.

The approval should be instantaneous, so if you do not receive an email in your inbox or junk folders, please let us know or you can chat with TI Customer Support right away. Customer support has the ability to look for your specific PSpice for TI request, which I do not have access to directly, and provide immediate assistance.


Thank you,
Manuel Chavez

Manuel,

I submitted the request again.  After submitting, I got the following message just like last time:

Thank you for requesting access to the PSpice® for TI design and simulation tool.

Your request will be reviewed - If you are approved immediately, you will receive an email in a few minutes. If you are not immediately approved, you should receive an email within approximately 24 - 48 hours (excluding weekends). Instructions and your access URL will arrive in an email sent from: pspice-for-ti@ti.com. This is a “no-reply” address. If you need access assistance, please contact us at Customer Support Center. To see a list of Frequently Asked Questions, click here. Thank you, Texas Instruments

This time, unlike last time, my request was immediately approved.

Thanks,

Kevin

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Kevin,

Thank you for confirming! This thread will be closed, so please let us know if something comes up using the red and yellow buttons in the upper right corner of this window.

We wish you success on your projects!


Respectfully,
Manuel Chavez