• State Resolved
  • Locked Locked
  • Replies 9 replies
  • Subscribers 42 subscribers
  • Views 5559 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LME49726 looking for PSpice model

Colin Marcus
Prodigy 120 points
Other Parts Discussed in Thread: BUF634, LME49726, LME49600, TINA-TI

I've been looking everywhere for a PSpice or LTSpice model for this op amp. Does one exist? I am not going to use the part if I can't model it first.

Alternately, if there's a similar part I could use, please let me know. I'm planning to use it as a unity gain output buffer into relatively low impedance loads (speakers with <50 ohms). The main thing that attracted me to this part was the low price compared to the BUF634.

Thanks for your help!

  • 0
    Prodigy 120 points

    I realized I should provide more details about my application. I am looking for a device capable of:

    - Rail to rail operation

    - Running off a single supply with Vss as low as 3V

    - Unity gain operation

    - Supplying at least 150mA, preferably more

    - Cheaper than the BUF634, which is about $7-8 apiece.

    - This is for audio, so reasonably low distortion / noise

    I chose the LME49726 because it appeared to do all of that for only $2. Of course, without a PSpice or LTSpice model it's hard to make sure my circuit will work as intended...

    Again, thanks for your help!

  • 0
    TI__Expert 3840 points

    Hi Colin,

    I'm not sure if you noticed, but there are TINA models on the webpage. If your simulation needs are small and quick you could download TINA for free and try that out. I understand that you may want to sim with other components using PSpice, so I have placed a question to the modeling guys regarding this for you. I'll let you know as soon as I hear something.

    Best Regards,

    JD

  • 0 in reply to John De Celles
    Prodigy 120 points

    Thanks for doing that, I really appreciate it.

    I'd much prefer to use the PSpice/LTSpice version, since I already have all my work in that program, plus I'd rather avoid having to learn a whole new program.

    Are there a lot of parts that only exist in TINA? This is the first time I've had this problem with a part made by TI.

  • 0 in reply to Colin Marcus
    TI__Expert 3840 points

    Hi Colin,

    It appears that there was a problem syncing up the literature number and the model in the database. This generally does not occur. Until they get the model into the database and up on the web, I am attaching the netlist (.lib) file here. Please let me know if this is sufficient.

    Thanks and Best Regards,

    JD

    0167.lme49726.lib

  • 0 in reply to John De Celles
    TI__Expert 3840 points

    Hi Colin,

    Just an FYI; the LME49600 and the LME49610 are very similar to the BUF634 and they are a little cheaper. The LME49610 has a 44V maximum operation voltage, but be aware none of the above products operate at 3V, all have a 5V minimum.

    The LME49726 is really a high output current RR op amp, whereas the parts above are only output stage buffers typically used in the feedback loop of another op amp. If you really need to operate at 3V then the LME49726 is a good choice.

    Regards,

    JD

  • 0 in reply to John De Celles
    Prodigy 120 points

    As far as I can tell, that is not a file format compatible with LTSpice. When I opened it in notepad, most of it appeared scrambled. I attempted to open it in LTSpice, and it threw a "too few nodes" error. Also, it didn't say anywhere in the readable parts of the file what the pin designations were.

    Please note that I am not an expert, so if I was supposed to convert it or something, I didn't.

  • 0 in reply to Colin Marcus
    Prodigy 120 points

    Ah yes, now I'm noticing that up at the top it says "Encrypted_Lib". What does that mean?

    Also, I am using an older version of LTSpice IV. If I update, will it be able to read this file?

  • 0 in reply to Colin Marcus
    TI__Expert 3840 points

    Hi Colin,

    I too am not an expert with all of the different packages. I have moved your issue to the modeling forum so that we can conclude this issue for you.

    Thanks and Best Regards,

    JD

  • 0 in reply to John De Celles
    TI__Mastermind 39210 points

    Hi Colin,

    The models that we release to the web are mostly encrypted and will only run in the simulator in which they are developed (encrypted PSPICE models will run in PSPICE 15.7 and up; encrypted TINA-TI models in TINA-TI only).

    If you need a unencrypted model, please request it through your local AFA. You might need to setup an NDA with TI for it. As an alternate the TINA model can be run in just a few easy steps:

    1. Download and install TINA-TI from here: http://www.ti.com/tool/tina-ti. It takes only a few minutes.

    2. Click on the TINA-TI Reference design on the product folder: http://www.ti.com/product/LME49726#simulationmodels. It should open in TINA-TI directly since you have installed it in Step 1.

    3. A typical application schematic should already be setup for you. From the top menu bar, simply click on Analysis --> AC Analysis -->  AC Transfer Characteristics and then click OK.   

    Thats it!. You should have the AC results for your design.

    Let me know if that works for you.

    Best regards,