SN74LVC1G97: Gated Oscillator with the 2 i/p NAND configuration and one inverted input

Emrys, I agree with you, I don't see any reason either - guess I'll just have to commit it to a PCB. And yep the big issue would be the size of that resistor, I'll probably go for 330K max as my Vcc could vary widely, accuracy of osc. not important.

Where have all the pspice models moved to? I though I'd refresh my database but the link nows point to nothing in the  Webench section. :-( 

Hey Tim,

We haven't gotten around to making all the configurable logic models yet - I can ask my team's modelling expert to put one together for you though.

Are you using PSpice for TI?  It keeps an updated library of TI models that can just be dropped into a simulation.  Otherwise, you can grab them from the product website - if one is available it should be there.

Hi Tim,

See the attached for the SN74LVC1G97's PSpice model.

SN74LVC1G97.zip

Thanks!

Chad Crosby

Emrys, I'm still using TINA TI - I registered for Pspice for TI and downloaded it but haven't plucked up the courage to install it yet - too much of a "transition level" at the mo! But I see Chad has a model for me!

brill

Hi Tim,

You can use the attached model with TINA also, you'll just need to change the .lib extension to a .cir.

Thanks!

Chad Crosby

Hey Tim,

I understand completely -- I still use Tina-TI for a lot of things, but I'm getting used to PSpice.

One thing to note on that model is that it's behavioral only -- it should give you a good idea of how the device works, but don't expect it to be 100% accurate to match the device. We tend to use the 'worst case' values in the model, so you'll probably see some differences in your final design.

Chad! Brill..... what else do you have in your bottom drawer?

I'm oscillating and gating now! The macro doesn't make it easy: "Where A = IN0, B = IN1, and C = IN2" differs from the datasheet and the example that Emrys posted

Now if the macro had "Where A = IN2, B = IN0, and C = IN1" it would be more consistent with the data sheet

but I'm rockin' now

Thanks
Tim

Chad, you wouldn't happen to have the 74LVC1G57 as well? So then I can do an XNOR

thanks
Tim

Thanks Emrys, so what would you say is the difference with Psice for TI ?
Thanks
Tim

Hey Tim,

I think the biggest advantage to using PSpice for TI is that it includes libraries of models that you can just drop in to your circuit. I feel like I've only scratched the surface with that software though -- I used the unix-based Cadence in school, and it's very similar, but there are enough differences that I'm constantly learning how to do things. That's why I often fall back to Tina if I just want to get something done quickly.

I've found that PSpice is a bit more robust than Tina-TI as far as how it handles spice code. It supports some better spice modelling techniques that our version of Tina doesn't support, but I think your average user won't ever run into those parts of the system. I spend a good portion of my time tinkering with spice models directly rather than designing systems around them.

There's a pretty good video series introducing the software here: https://training.ti.com/pspice-ti-introduction

I like that the videos are kept short and to the point.

Hey Tim,

I managed to pull something together. See the attached:

2251.SN74LVC1G57.CIR

Thanks!

Chad Crosby

Thanks Chad, I'm replying again as I can't see my post. I think it's to do with the E2E update and the clearing the cache (which I don't want to do on my favourite browser).

Line 171 of the macro needed a parenthesis mod, either one in or one out, seems to work for me as I got tt to oscillate.

Also I undertsand now the issue of "Where A = IN0, B = IN1, and C = IN2"

every blessing
TIM