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LTC6409 ltspice model importing

Other Parts Discussed in Thread: OPA847, TINA-TI, LMH5401

Hello,

I'd need to use the LTC6409 fully differential amplifier in TINA9-TI. However after downloading ltspice and looking for a proper model, I cannot find it among the .sub files. I can just find the LTC6409.asy in a different folder. I cannot see where is the actual file I need to import in this case. I'm new with Spice and related programs. What should I do to solve this problem?

Thanks in advance,

Francesco 

  • Hi Francesco,

    I did a lot of searching and did find the netlist for the amplifier you mention. When I view the netlist with a text reader I see that the first circuit inside the model has an "A" designation. That indicates that it uses a proprietary  transconductance amplifier function that is not compatible with TINA Pspice. 

    Since the model is the property of one of our competitors we cannot delve into the model. You may want to contact the model owners and ask if they have a Pspice compatible version of the model. If it exists, then it should run in TINA and other Pspice based simulators.

    Regards, Thomas

    PA - Linear Applications Engineering

  • Hello,

    thanks for your quick answer. 

    This is my problem: I've  designed a 100 MHz trans-impedance amplifier exploiting a OPA847, for quantum optics applications. Now I'd need to design a faster trans-impedance amplifier (above 200 MHz), and I read a paper where they claim that the fully differential amplifiers could be a great substitute of the opamps as OPA847. Do you have any fully differential amplifier with similar features to LTC6409 in term speed and noise? I found that the LHM5401 has quite similar speed and general characteristic (I've to say that I am a physicist without a good background in amplifiers).

    Before starting to design it I'd like to have a deeper understanding of the LHM5401 features, so I'd need to simulate my transimpedance amplifier as faithfully as possible.

    My question is: does the Tina-ti model for LHM5401  have the noise characteristics included (eg. input voltage noise, current voltage noise)? How are they modeled? I cannot quite understand how to figure it out.

    Regards,

    Francesco

  • Hello Francisco,

    When I look over the LMH5401 model netlist it does list input voltage noise as being modeled, but nothing is mentioned about input current noise being modeled. Actually, the OPA847 and LMH5401 are products from TI's High Speed Amplifiers group which is a different group than Precision Amplifiers that I am part of. The engineers who support those products can best answer your questions about the model capabilities.

    If you would like I can move this thread to their E2E forum, but didn't want to do so without your okay.

    Regards, Thomas

    PA - Linear Applications Engineering

  • Hello,
    yes thanks, it would be great if you could forward my issue to the High Speed Amplifiers group, if you say that can help.
    Thank you again for the quick reply.
    Regards
    Francesco