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ADA8282 SPICE model failure

I've simulated this:

In LTspice but it behave weird I can't understand my fault, I think maybe the model have problem?
I've downloaded the model from ADA8282 ADI page.

Also I've followed it's evaluation board approach UG-846:

still the problem exist.

New question rises: why they've used C5, R5 and R4? 



New information added.
[edited by: mohammadsdtmnd at 2:48 PM (GMT 0) on 12 May 2019]
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  • Thank so much, have you tested it for long time, will it stay stable for 1 secound?

    Look, in first one millisecond I have what you've achieved, but it deviate as the time passes:

    Thanks for your sharing of model, as I think our models are the same except for it's model pin arrangement, I didn't upload it but only check on your model for long time simulation.

    The best requard

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  • Hi mohammadsdtmnd,

    Yes, I see the same strange behavior of the model if I let Transient Response run beyond about 45ms. I cannot tell what's causing the ADA8282 model to misbehave like that!

    The Spice model file does hint that the model may be very minimal, copied below:

    "*This model was created for the purposes of simulating functionality only.
    *Parameters modeled include:
    * Output Voltage Swing
    * Bandwidth
    * Functionality at 36dB gain
    * Supply current"

    I think in normal applications dealing with typical signal frequencies / periods, that's a probably a "don't care".

    Is there a particular reason that you need to let your simulation run that long?

    Regards,

    Hooman

  • Hi Hooman!

    Since i'm begginer i though maybe the problem is in my design. It seems that it is the model intrinsic. thanks.
    There is a question, what is that-ended source you've used in your schematic?
    Please mention this diability in SPICE model hints. 

    regards!

  • Hi mohammadsdtmnd,

    I think you are asking about the source E1 in my schematic?

    That's just a "voltage dependent voltage source" to help me create the differential input by specifying its gain to be "-1V/V" so that it'd be inverted compared to the other source V1.

    I'll forward the question about the misbehavior of ADA8282 pspice time-domain transient response issue going past 45ms to people in charge and if I get a resolution I'll post it here.

    Regards,

    Hooman

  • Hi Hooman, thank you so much.

    best regard.