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SN54ACT00: Need IBIS model

Scott Asher
Intellectual 500 points
Part Number: SN54ACT00

Hello, Can you provide an IBIS model for the SNJ54ACT00J? If one is not available, can you provide a model of another part that would provide close to the same simulation results as the SNJ54ACT00J? If so, what would the differences be?

Thanks,

Scott

  • 0
    TI__Guru* 96681 points
    Hey Scott,
    I would recommend using the IBIS model provided for the commercial version of the device:
    www.ti.com/.../toolssoftware

    The package parasitics will be slightly different, but at the frequencies that these devices operate, I would expect very minimal difference in the signal integrity for your analysis. The transmission line will typically have far greater effects.
  • 0 in reply to Emrys Maier
    Intellectual 500 points
    Hi Emrys.

    Thanks for info! I have some follow up questions on this. You mention there will be minimal difference in the signal integrity for the analysis. I'm interested in simulating the PCB trace flight times. So using the 74 model in place of the 54 may work to measure flight times if the 54 and the 74 have the same tPLH and tPHL delays in the datasheet. But what do we do in cases where the 54 has slower tPLH/tPHL specs than the 74 version? I would suspect this means that the rise/fall times of the 54 are slower than the 74 such that the 74 model could not be used to accurately simulate what the flight times would be for the 54 right? What do we do in this case?

    Thanks,
    Scott
  • 0 in reply to Scott Asher
    TI__Guru* 96681 points

    Hey Scott,

    I should start by giving the caveat that I'm not an expert on our military parts -- there's a possibility that the '54 version of this device is radically different internally than the commercial version (but I doubt it).

    We can only guarantee the propagation delay within the datasheet range -- it's listed as 1 to 9.5ns in the datasheet, so any value in there is possible. The IBIS model will give you an idea of the output response of the device, but it won't tell you the exact propagation delay for every single device that comes out of our factory -- and since it's a computer model, it will just show you the same delay every time.

    The system must be designed to the worst case -- which might mean making sure it will work with anything between 1ns and 9.5ns of delay.