PSPICE-FOR-TI: Simulation error and ACF Forward with UCC2897A model

Micky Shih

Prodigy 230 points

Part Number: PSPICE-FOR-TI
Other Parts Discussed in Thread: UCC2897A

Hi all

what is "ERROR(ORPSIM-16296): Invalid Expression: Specify either current(I) or voltage(V)."

Is there an established circuit that contains ACF Forward and IC UCC2897A ,Thanks.

over 5 years ago

0 John Stevens over 5 years ago

TI__Expert 7395 points

Micky,

Thanks for your interest in UCC2897A and TI here. Can you attach your simulation file? I'll assign to an apps engineer to support your questions.

Regards,

John

0 Micky Shih over 5 years ago in reply to John Stevens

Prodigy 230 points

Hi John,

This is the file I downloaded. Can I modify this file to the voltage and current I want?

Thanksslum429.zip

0 Hong Huang over 5 years ago in reply to Micky Shih

TI__Guru 74075 points

Hi,

You can modify either voltage or current but if your modification is outside of the existing design can do then you need to modify associated component values together.

0 Micky Shih over 5 years ago in reply to Hong Huang

Prodigy 230 points

Hi Hong,

OK, in addition, is there a way to modify the simulation time, or can I close the values that do not need to be displayed, because the simulation time is too long,

Thanks

0 Hong Huang over 5 years ago in reply to Micky Shih

TI__Guru 74075 points

Hi,

Yes, you can do these. You need to follow what PSpice instructions how to do them.

0 Micky Shih over 5 years ago in reply to Hong Huang

Prodigy 230 points

Hi Hong,

But he didn't let me modify the simulation time, it seems to be locked, can I provide more detailed information,

Thanks

0 Hong Huang over 5 years ago in reply to Micky Shih

TI__Guru 74075 points

Hi,

You need to save the project to a new one, such as to a new folder from PSprice. Then you can change the simulation time.

0 Micky Shih over 5 years ago in reply to Hong Huang

Prodigy 230 points

Hi Hong,

OK, I will try it.

May I only display the voltage and current of the installed probe, and not display the other ones that are not installed, so that the simulation can run faster.

Thanks

0 Hong Huang over 5 years ago in reply to Micky Shih

TI__Guru 74075 points

These should be your options.

0 Micky Shih over 5 years ago in reply to Hong Huang

Prodigy 230 points

Hi Hong,

Where should I set up? Is it set from Simulation Setting? Is there a more detailed explanation,

Thanks

0 Hong Huang over 5 years ago in reply to Micky Shih

TI__Guru 74075 points

Hi,

After you open "UCC2897A_TRANS.DSN"

click as above until your see PAGE1*, then double click PAGE1*, the schematics will show.

Then click File then "Save Project as" to a new folder.

Now you can change the simulation time.

0 Micky Shih over 5 years ago in reply to Hong Huang

Prodigy 230 points

Hi Hong,

I follow your way and modify the circuit diagram. No matter how you change it, the output is the same as the original one. I wonder if it is still locked and the simulation results have not changed.

Thanks

0 Hong Huang over 5 years ago in reply to Micky Shih

TI__Guru 74075 points

You can create your folder anywhere on your computer. After create a new folder then open pspice and follow the steps I described.

0 Micky Shih over 5 years ago in reply to Hong Huang

Prodigy 230 points

Hi Hong

I modified the feedback resistance value and the switching frequency resistance setting of the IC, but my Mosfet did not work, resulting in no output voltage. May I ask which part of the problem might be wrong.

Thanks

0 Hong Huang over 5 years ago in reply to Micky Shih

TI__Guru 74075 points

Hi,

If before modifying the circuit can work and after modifying cannot, the issue is on your modifying or on your Pspice setup. You would have to figure out where is wrong.

I suggest you use the original MOSFETS to make simulation. If new MOSFETS cannot work you need to talk to your MOSFET provider.

Another is your simulation setup but that has to be on your debugging for example if your simulation time is too short.

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PSPICE-FOR-TI: Simulation error and ACF Forward with UCC2897A model