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spice model for THS4531, THS4531A and THS4532

Richard Kolman
Prodigy 50 points
Other Parts Discussed in Thread: THS4531, THS4531A, THS4524, THS4522, THS4521

I think there are errors in the spice models for the THS4531, the THS4531A and TH4532.

The THS4531.TSC example (in EXAMPLES\TI Test Circuits) yields an operating current of almost 50mA, yet the data sheet claims an operating current of 250uA.

If you let the SD\ pin float, it is 250uA but the GBW is nowhere near correct.

When I change the THS4531 to the THS4531A or THS4531, the same problem happens.


When I use the PSPICE model(s) for all three in a PSPICE-capable simulator, the same problem happens.

FYI, the ths4521_ths4522_ths4524.TSC does give both the correct operating current and bandwidth with the SD\ pin tied to V+.

  • 0
    TI__Prodigy 220 points

    Hi Richard,

    When I tested the example circuit and probed for current from the DC voltage source, I could see a 19.9 mA supply current.

    But when probed for current at the device pins, the value is 250 uA. This is because the PD pin is drawing 19.6 mA current and the device is still drawing 250uA.

    You can ignore the PD current since it is not modelled correctly in TINA. If you look at the THS4531 Datasheet, the Disable Pin bias current is 50nA TYP.

    Also the PD pin should be tied to VDD and should not be floated.

    -Eldho

  • 0 in reply to Eldho George
    TI__Genius 12631 points
    Hello Richard,
    Thanks for bringing this to our attention. As Eldho pointed out there is an error in the PD circuit that is causing the extra current draw. We are in the process of refreshing some of our TINA models and the THS453x is on the list. We hope to have an updated model in the next month or so.
    -Samir
  • 0 in reply to Eldho George
    Prodigy 50 points
    Thanks, Eldho.

    I modified my spice circuit to use a separate source to power the PD pins, and now the VDD operating currents are correct.
  • 0 in reply to Samir Cherian
    Prodigy 50 points
    Thanks, Samir!

    I check for updated models frequently, so I look forward to that.