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Original question:

TINA/Spice/SN74LVC1G74: where can I find the pspice or TINA model of SN74LVC1G74

TINA/Spice/SN74LVC1G74: SPICE model available yet?

Michael Roberts20
Prodigy 50 points
Part Number: SN74LVC1G74
Other Parts Discussed in Thread: TINA-TI

Tool/software: TINA-TI or Spice Models

Hello,

I wanted to see if a SPICE model had been created for this part yet.  I was unable to find one through the TI website.  Is there one available that can be shared? 

I understand that I could create my own and turn it into a macromodel, but I would like to use a "COTS" one if it had already been made.

Thanks,

Mike

  • 0
    TI__Guru* 97046 points
    Hi Mike,
    I'm afraid that we don't have a functional DFF PSpice model available right now. We're currently working on some technical challenges surrounding PSpice and devices that have internal memory (Flip-Flops and shift registers, specifically).
  • 0 in reply to Emrys Maier
    Prodigy 50 points

    Thanks for the quick follow up Emrys.  Any suggestions on similar parts or ways to simulate this?  Or is the best solution to just "get it and try it"?

    I posted the functional block diagram below also.  Is the challenge in SPICE to get the TG (transmission gate, I think) blocks working properly?

  • 0 in reply to Michael Roberts20
    TI__Guru* 97046 points
    The biggest trouble is making it work fast and accurately at all frequency ranges.

    I can build the above block diagram -- and, in fact, I have. If I do this with ideal gates, ie input = 1 or 0 and output = 1 or 0, then we run into problems with the transmission gates creating voltage spikes and values other than 1 or 0.

    I've tried working around this by adding thresholds to the inputs, but that makes the whole thing so slow that I can't realistically use it.

    The best solution I've found so far is to idealize the internal circuit so it stores a value without the master-slave latch configuration (which is how real DFFs are made). This does work very well and runs fast, but it won't work across all frequencies -- ie I can optimize it to work around ~1 kHz _or_ I can get it to work in the ~100 MHz range -- so far I haven't been able to get Tina-TI to correctly operate the device at both frequency ranges without modifying the simulation parameters.