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LM6172: PSPICE Model

Part Number: LM6172
Other Parts Discussed in Thread: TINA-TI, OPA2690, LM7372

Hi,

Are the noise parameters included in LM6172 PSPICE model ?
I couldn't find a comment on the noise parameters if using the netlist viewer and searching a phrase "noise" with TINA-TI.

Best regards,
Kato

  • Hello Kato-san,

       You are correct, the netlist viewer does not seem to indicate that noise has been modeled for this device. I also ran a few tests that proved this point. Unfortunately, you would not be able to run noise simulations using the LM6172 PSPICE model.

    Thank you,

    Sima

  • Hi Sima-san,

    Thank you for your prompt reply.

    I understand.

    Best regarads,
    Kato

  • Hi Sima-san,

    I just got a request from our customer, so could you please provide me LM6172 PSPICE model with the noise simulation model(1/f noise and so on) ?

    Best regards,
    Kato

  • Before you get too far with this, I tried to find an internal cross and failed - not sure what this means, but it is unlikely any model updates are available. 

    The OPA2690 is a similar topology internally, but not as high a supply voltage, 

  • Hi Michael-san,

    Thank you for your prompt reply.

    Our customer has already used LM6172. Unfortunately, as you have pointed out, OPA2690 doesn't meet the requirements with the maximum operating voltage range.
    So, could you please make the LM6172 PSPICE model including the noise parameters ?

    Best regards,
    Kato

  • Well, modifying the TI model would require product line attention - and, they will likely find many other things to improve on that model. 

    Anyway, before they take off on that, here is a parametric search for close parts (TI/NSM only, LTC does also have a similar dual). The LM7372 looks promising from a spec fit standpoint, - this is VFA sorted descending Slew Rate, Looks like it might be a slight decomp on the LM6172. So, if you have any gain at all should be fine, 

    And, TINA V11 has a model for the LM7372, testing it for input noise looks pretty darn good - 1/f and flatband looks right, 

    Here is the TINA file for this, there is always a question of model validity across other specs, but the noise voltage looks good, This test ckt emphasizes the input voltage noise for the op amp itself. 

    LM7372high gain test.TSC

  • And, the LM7372 is still in the older parametric cross reference (the LM6172 is not). These are abysmal crosses, but it does show a different database list of parameters for the LM73272 re-iterating that 14nV flatband noise in the sim and the previous parametric list. 

  • Hi Michael-san,

    Thank you for your support.

    I understand that it is hard for you to modify LM6172 PSPICE model.
    As you mentioned, it seems that the noise parameters are included in LM7372 PSPICE model. So, I will suggest our customer to use LM7372 PSPICE model instead of LM6172 PSPICE model.
    I will contact you if I get additional questions from him.

    Best regards,
    Kato