LMR51610: How to use the model data for PSPICE

Hi Kazuhiro

Thanks for using our products!

I'll take a look and get back to you on Monday

Thank you

Regards

Onkar Bhakare

Hi Onkar.

Thank you for reply.

for your information, the part we want to use in our product is the LMR51610-Q1.

In our prototype, using LMR51610XFDBVR and LMR51610YFDBVR.

Regards

Hi Kazuhiro

kazuhiro haga said:

The second problem is that when i run PSIPCE on a simple circuit like the one below using the latest model data, PSPICE does not complete the calculation job even after a day. If i use the sample project included to the model data, PSPICE completes the calculation job in just a few minutes. When I use the model data into a circuit, the model data is displayed as LMR51450_TRANS. Is the inside of the model data normal?

Did you check with LMR51610 model? - https://www.ti.com/lit/zip/slum874

I checked with on my system, it is working for me

kazuhiro haga said:

The third problem is that LMR51610 has two switching frequencies, one is 400kHz and the other is 1.1MHz. How can I change the switching frequency in the model data?

I am checking this internally with creator of the model. I'll get back to you once I hear from him.

Thank you

Regards

Onkar Bhakare

> Did you check with LMR51610 model? - www.ti.com/.../slum874
> I checked with on my system, it is working for me

Yes, I used it.
I opened "lmr51610_spice.opj" in slum874.
and i used "LMR51610 START-UP SIMULATION".
in the case, it can quickly complete the calculation and display the simulated waveform.

But if used model data of "LMR51610_trans.OLB" in slum874, can not completed calc.
Here are the steps on how to use the model. The steps should be correct.
in the case, Why can not completed calc?

step1:  add the OLB file.

step2: select and place the LMR51610_TARANS.

Step 3: add file path of the OLB file to the simulation settings.

thanks.

Hi Kazuhiro

I am getting the same issue when I try to place select and place the LMR51610_TARANS. Looks like there issue with file. Let me check with its designer.

Thank you

Regards

Onkar Bhakare

We shared there issue. i am looking foward to solve.

thanks.

Sure Kazuhiro

I have reached out to the model designer. I'll get back to you as soon as I hear from him

Thank you

Regards

Onkar Bhakare

I appreciate your great support.

Regards

Hi Kazuhiro

Sorry for the delay 

Model designer is not currently in our BU so it is taking some time to get feedback. Most like likely LMR51450_TRANS model is modified to get LMR51610 so you're seeing that.

Thank you

Regards

Onkar Bhakare

Hi Kazuhiro

Do you have NDA with TI? if yes could you please share details?

Thank you

Regards

Onkar Bhakare

Sorry for my late reply.
Last week was collection of public holidays in Japan.


I don't see the point of your question however,
We have purchased your products via trading agent.
The trading agent have package contract including NDA with TI.
We have trading contract including NDA with trading agent.
if will survey to take a long time whether  we had directly NDA with you.

Regards

We are getting off track.
Let's review what we discussed.

We are sharing the same issue when We try to place select and place the LMR51610_TARANS.
Therefore, we hope to get model data that be able to job in just a few minutes.

We opened "lmr51610_spice.opj" in slum874.
and we used "LMR51610 START-UP SIMULATION".
in the case, it can quickly complete the calculation and display the simulated waveform.

I have an important announcement.
I realized that simulation time is set very short about "LMR51610 START-UP SIMULATION".


This short amount of time is not enough to reproduce device's behavior.
This designer is trying to play us.

LMR51610 is a new product from TI.
So TI still have room for improvement that to encourage sales increase.
It is to modify spice data.

Regards

Hello Kazuhiro

I ran it for 3ms and It is working fine at my side. PFA waveform

Thank you

Regards

Onakr Bhakare

Hello Kazuhiro

Kindly try the same at your side and let me know if this helps

Thank you

Regards

Onkar Bhakare

Thank you for your suggestion.
I was using profile you suggested and confirmed that the simulation calculation was completed in a short time.
I am contented with the starting behavior　of LMR51610.

There are two behaviors I want to check with PSPICE.

The first is behavior in response to load fluctuations. When the current flowing through the load fluctuates, the output voltage will fluctuate if the performance of the power supply IC is poor.

The second is behavior in response to input voltage fluctuations.
For instance, instantaneous interruption, ripple, noise and spike pulse superposition.

Therefore, the "run to time" required is 1 sec or more.

Thank you

Regards

Hello Kazuhiro

kazuhiro haga said:

The first is behavior in response to load fluctuations. When the current flowing through the load fluctuates, the output voltage will fluctuate if the performance of the power supply IC is poor.

The second is behavior in response to input voltage fluctuations.
For instance, instantaneous interruption, ripple, noise and spike pulse superposition.

This should be possible in few ms. You'll be able to capture required behavior within 10-20 ms or less.

Let me know if need further help

Thank you

Regards

Onkar Bhakare

So here's a question. I want to check behavior after starting up. LMR51610 should need to wait about 5sec to stabilize the output voltage. I want to check the behavior a few ms after more than 5 seconds have passed. Please try running this simulation.

I think you will find that the simulation calculation you proposed, which is just a few ms, will take more than few days to complete.

Regards

Hello Kazuhiro 

I agree 5 sec will take quite a lot of time. I have seen this before. Let me check for this design at my end.

Thank you

Regards

Onkar Bhakare

I would like to check this.

If you were able to get how to set startup profile, could you please tell me it.
Regards

Hi Kazuhiro

Whether that 5s time in between is necessary? As it is taking quit a lot of time to simulate and simulation is stopping in between. This device has fixed internal soft start time of 2.3 ms and output will get settled within that 3 ms. After that we can apply the load step. I understand, in real application there might load transient after 5s however we don't to simulate exact profile. Simulation profile of 5-6 ms should work here. I'll reduce simulation time and share the results with you.

Thank you

Regards

Onkar Bhakare

Hi Kazuhiro

Check the plot of load transients after startup is complete

Load Transient plots.zip

Thank you

Regards

Onkar Bhakare

Hi Kazuhiro

Check this one taken for slightly longer duration

Hope this helps

Thank you

Regards

Onkar Bhakare

>> Load Transient plots.zip

Yes, I would like to do it.

How long did it take you to get this result?
Please tell me how to set this profile.
I would like to add surge voltages (ex load dump) such as ISO16750-2 and ISO7637-2 to the results you have created.

Thank you

Regards

Hi Kazuhiro

I'll share the file with you tomorrow IST. 

Thank you

Regards

Onkar Bhakare

Thanks for making the files.
This files seems to have been edited with an older version of Orcad or PSPICE.
If running this file in the latest version of PSPICE for TI, become in strange behavior.
I tried changing this files setting but it didn't go well.

The error message is Japanese.
It means, "Title: Server in use. This task can't be completed because another program is busy. Please push Change Button,  and select to the busy program and resolve the problem."
This message repeats forever, so I quit it from Task Manager.

Regards

Hello kazuhiro

We have created the shared model in following version 

Kindly confirm yours

Thank you

Regards

Onkar Bhakare

Yes, your software is the latest version, me too same version.
Do you already know this problem?
Can you please tell me the solution?

1. open the file “lmr51610_spice.opj”

2. conversion wizard about old version will start.
select to "Convert the project", and click "next".

3. click "finished"

4. come up conversion report.
click "close".

5. come up warning message "ORCAP-2461".
click "ok".

6. Open the following file:
"Design Resources" -> ".\lmr51610_spice.dsr" -> "Steady_State" -> "PAGE1"

7. create a new simulation profile.

8. add profile name, and click "create".

9. add to library the lmr51610.

10. set to each time param.

11. run this simulation.

12. come up message "ORCAP-15051".
click "yes".

13. occurs error, and it aborts to running simulation.
ERROR(ORPSIM-15461): Incorrect number of interface nodes for X_U1.

Regards

Hello Kazuhiro

I am getting the initial prompt while opening the file. Probably I am using PSpice for TI. You can also try that, it is free to use. Moreover, I don't think you need to add configuration files. 

Thank you

. Regards

Onkar Bhakare