SN74LV123A: SN74LV123ATPWRG4Q1

Masayuki Uchihara

Part Number: SN74LV123A
Other Parts Discussed in Thread: TINA-TI

Hi Team,

Could you review my PSPICE simulation result? My simulation result is not same with the datasheet value. I want to know your consideration.

My simulation result

The data sheet

Thanks,

Uchihara

over 3 years ago

0 Chad Crosby over 3 years ago

TI__Expert 6680 points

Hi Uchihara-san,

I'll recreate this simulation on my end and get back to you on this.

In the meantime - What software are you using to simulate this device?

Thanks!

Chad Crosby

0 Masayuki Uchihara over 3 years ago in reply to Chad Crosby

TI__Intellectual 1635 points

HI Chard,

Thank you for your quick reply. This is TI-Pspice.

Regards,

Uchihara

0 Chad Crosby over 3 years ago in reply to Masayuki Uchihara

TI__Expert 6680 points

Hi Uchihara,

Please allow me a few days to get this simulated for you.

Thanks!

Chad Crosby

0 Takuma Ito over 3 years ago

TI__Expert 5200 points

hi Chad

I am taking over this from Uchihara-san. could you tell me the status?

0 Chad Crosby over 3 years ago in reply to Takuma Ito

TI__Expert 6680 points

Hi,

Sorry for not updating this thread - I tested the model on my end, and determined that I'll need to create a new model for this device. I'm working on that now, and I should have that ready in the next couple of days.

Thanks!

Chad Crosby

0 Takuma Ito over 3 years ago in reply to Chad Crosby

TI__Expert 5200 points

hi Chad,

Thanks for confirmation! So, the issue was caused because the model had issues?

0 Chad Crosby over 3 years ago in reply to Takuma Ito

TI__Expert 6680 points

Yes,

We've been working on our end to create a reliable latching circuit (which is used in this circuit), and I'm going to create a model with our new latching circuit. The old one is prone to issues - which is why I've been reluctant to update models like these on the web.

I'll try to get this back to you ASAP to help with your testing.

Thanks!

Chad Crosby

0 Takuma Ito over 3 years ago in reply to Chad Crosby

TI__Expert 5200 points

hi chad

One additional question, in order to set 100ms, 1uF and 100kohm combination can be used?

0 Chad Crosby over 3 years ago in reply to Takuma Ito

TI__Expert 6680 points

Hi,

According to section 10.2.1.2 of the datasheet, yes, this should give you 100ms.

Thanks!

Chad Crosby

0 Takuma Ito over 3 years ago in reply to Chad Crosby

TI__Expert 5200 points

hi Chad

could you give me update on revising the model?

0 Emrys Maier over 3 years ago in reply to Takuma Ito

TI__Guru* 96591 points

Hello,

I still don't have a 100% bug-free and guaranteed model, however I have built one that seems to be functional. For some reason, you have to keep Cext connected to AGND in this version or the model will fail to operate (still tracking this bug down).

Monostable multivibrators are notoriously difficult to model.

That being said, I can share my current version of the model that you can work with some -- it should give you a reasonable estimate of operation for basic simulations.

I would still recommend to build a prototype and test for final performance in your system, and expect to adjust Rext to meet your exact timing needs.

LV123_beta.TSC

0 Takuma Ito over 3 years ago in reply to Emrys Maier

TI__Expert 5200 points

Hi Emrys

thanks for the update. the attached file is .TSC, which is for Tina-TI in my understanding. Is it possible to use this in PSPICE for TI?

0 Emrys Maier over 3 years ago in reply to Takuma Ito

TI__Guru* 96591 points

I have tested in Cadence PSpice and found that this version fo the model will not converge in that simulator. It seems that it will only work in Tina-TI and only under some circumstances.

I don't expect to have a fully functional model any time soon - this has been a long-time project and is still in work.

0 Takuma Ito over 2 years ago in reply to Emrys Maier

TI__Expert 5200 points

hi Emrys

What is target date for completing model for PSPICE? customer need PSPICE one, not TINA model.

0 Emrys Maier over 2 years ago in reply to Takuma Ito

TI__Guru* 96591 points

There is no completion date planned - this is an experimental model and it may not ever function. Please see this FAQ: https://e2e.ti.com/support/logic/f/logic-forum/787588/faq-why-is-there-no-pspice-model-for-a-monostable-multivibrator-device

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SN74LV123A: SN74LV123ATPWRG4Q1