TLE2426 simulation not splitting Vin by 2 exactly

Discussion in 'General Electronics Chat' started by Dritech, Dec 29, 2015.

  1. Dritech

    Thread Starter Well-Known Member

    Sep 21, 2011
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    Hi,
    I was doing some simulations on the TLE2426 “rail splitter”. The datasheet states that it should provide a precise Vout/Vin ratio of 0.5.
    Why am I getting 2.537V when the input is 5V? Also, does it make a difference if the noise reduction capacitor is electrolytic or non-electrolytic?
    Below is a screenshot of the simulation:
    PS. I tried the same circuit on another simulator and I got the same results.

    [​IMG]
     
  2. Veracohr

    Well-Known Member

    Jan 3, 2011
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    75
    Have you verified the input voltage to the same accuracy?
     
  3. Dritech

    Thread Starter Well-Known Member

    Sep 21, 2011
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    Yes, the input is at 5.000V.
     
  4. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Add a load between each power rail and your new V/2 virtual ground.
     
  5. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    I just checked the datasheet. Should be 2.525 at max for a 5V input from 0 to 20mA. It looks like your virtual component in your simulator is out of spec. Did you get it directly from the manufacturer and/or on of their big distributors? If you got it from a Chinese supplier off of eBay, I am not surprised it is out of spec - it could even be counterfeit.
     
  6. Dritech

    Thread Starter Well-Known Member

    Sep 21, 2011
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    Thanks for the reply. Below is a snapshot of the datasheet. It states that at 5V input voltage, the typical output should be 2.5V.
    I only tried this on simulation and not in prectice.

    [​IMG]
     
  7. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    I understood that, I was just trying to be funny.
     
  8. DickCappels

    Moderator

    Aug 21, 2008
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    The maximum is 2.52, so yhe 2.537 you see is within the specification.
     
  9. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    I've been on vacation for a while now so my brain may not be fully engaged but,... Since when is 2.537 within the specified range of 2.48 and 2.52?
     
    Dritech likes this.
  10. DickCappels

    Moderator

    Aug 21, 2008
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    @GopherT you are corect. Got things mixed up while scrolling up and down the thread while walking in a crowded Bangkok shopping center.
     
  11. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    One night in Bangkok makes a hard man humble.

    Not much between dispare and ecstasy.
     
  12. PeterCoxSmith

    Member

    Feb 23, 2015
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    Does it matter? It's only a calculation!
     
  13. #12

    Expert

    Nov 30, 2010
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    Exactly.

    Your title says the chip is not acting correctly, but you don't have the chip. You are only playing with a simulator. You should be asking about how to fix the simulator.
     
  14. Dritech

    Thread Starter Well-Known Member

    Sep 21, 2011
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    My concern is that I am doing something wrong on simulation since I obtained the same output with two different simulation software.
     
  15. #12

    Expert

    Nov 30, 2010
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    Exactly.
    Your title seems to say the chip isn't splitting the rails precisely. I clicked in expecting to see a circuit problem. It's not a circuit problem. Worse, I don't know how to change the title of a Thread, so I can't help you there, either.
     
  16. DickCappels

    Moderator

    Aug 21, 2008
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    ahhhh...its a simulation!

    Your circuit looks simple enough. If the simulation, including temperature and Vin, does not exceed the device's specifications then I would turn my suspicion to the device model.
     
  17. dannyf

    Well-Known Member

    Sep 13, 2015
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    The datasheet didn't say that.

    That's just a little bit off spec per the datasheet.
     
  18. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    The point is, danny, that it makes no sense for a simulation model to be "out of spec". It is so easy to just enter the right numbers or, just as easy, the manufacturer should supply pertinent information on the datasheet of why a value would creep outside of the specification.
     
  19. dannyf

    Well-Known Member

    Sep 13, 2015
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    A rail splitter is nothing but an opamp follower. Depending on your current needs, it can be sized fairly easily.
     
  20. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Still not relevant. Please read above posts.
     
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