Dual Opamps +/- 12V supply

Discussion in 'General Electronics Chat' started by anand3001, Sep 26, 2009.

  1. anand3001

    Thread Starter New Member

    Sep 25, 2009
    4
    0
    Hello All,

    I am looking for a low cost (<$0.80) dual opamp able to run from ±12V.

    Does any one have any suggestions?

    Thanks for your help
    Anand
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    For what?

    What will it do?
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Here are some possibilities for you:
    Audio applications; TL072
    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=497-7659-5-ND

    Similar to TL072 but higher noise, less cost, for general purpose:
    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=LF353NFS-ND
    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=296-1781-5-ND

    For automotive applications (wider temp range)
    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=LM2904NFS-ND
    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=LM2904NGOS-ND

    Low power:
    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=MC33172PGOS-ND

    None of these are rail to rail, but are good for many purposes. If you need something more specific, you can use parametric search engines at various distributor and manufacturers' websites.
    I find Mouser.com search engine to be quite helpful.
    Digikey.com is fairly good.
    Fairchild has a decent search engine.
    National does too.

    If you can give more specifics about what you are trying to do, perhaps we can suggest something that will work well for you.
     
  4. kkazem

    Active Member

    Jul 23, 2009
    160
    26
    Hi all,
    Selection of an op-amp is no trivial task. It is something that should be carefully considered in light of what it task or specifications it has to function to. For newbies, it is a often little understood art (actually a science). Admittedly, many op-amp circuits allow for a wide selection and use of almost any op-amp, but then again, equally as many circuits require very specific op-amp specs. This requires the circuit designer to fully understand the datasheet specifications and how they affect the circuit performance. So, you're really asking the wrong question. It should be: "what op-amp specs are critical for the circuit function and circuit specs for my design." Since you gave no information on what the function of the op-amp circuit is, nor did you provide us with any of your required or desired design specifications for the op-amp circuit, we can't really help you much. I'd recommend that you peruse the app-notes section of Linear Technology, TI, National Semiconductor, and On-Semiconductor. There are many others, but that will give you a good start.

    If you want to, reply with the circuit function and specs for your op-amp circuit and I'll answer with specifics.

    Good luck.

    Kamran Kazem,
    kkazem
     
  5. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    Power supply is not the issue, almost any op amp will do that (such as a 741). Frequency response, slew rate (how fast can an op amp switch like a digital gate), linearity (a LM324 is a quad, it has some crossover distortion, but it would worK), noise, and DC stability are the big factors.
     
  6. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    Cheapest is probably LM358.
     
  7. anand3001

    Thread Starter New Member

    Sep 25, 2009
    4
    0
    Hello all,

    Thank you all for your replies. I appreciate your interest and do apologise for the inadequate information. I am designing a low cost data acquisition system with input analog isolation. Hence noise is not an important consideration nor is slew rate, but offset voltage should be < 1mv preferably.
    I have already searched all the major manufacturers web sites and used their parametric searches. I have found some dual opamps that will meet my specs but they work off only +/- 6V or less. I have found single opamps that will work off +/-12V but not dual opamps. I would ideally like to save space since I have to accomodate 8 channels on a 3U x 160 mm card size.
    Hope this helps a bit more. once again thanks a lot. ALL suggestions are most welcome and appreciated.

    best regards
    Anand
     
  8. bertus

    Administrator

    Apr 5, 2008
    15,647
    2,346
  9. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Hi Bertus,
    you listed the "typical" input offset voltage.
    But you cannot buy an opamp that has the typical spec, you get whatever they have which might have the "maximum" input offset voltage which is 16.7 times higher.
     
  10. anand3001

    Thread Starter New Member

    Sep 25, 2009
    4
    0
    Hello All,

    Thanks once again for the suggestions. Still havent found what I am looking for. Bertus, sorry but unfortunately 'typical' does not guarantee compliance to the < 1mV spec.
    Wookie, thanks for your suggestions - they were good, the LM 358A got close but not right.
    I have realised that I couldnt find any opamps through the parametric searches earlier because I always selected the offset parameter first and then selected the dual supply collumn.
    Actually I found an obscure opamp from Rhom - BA4560 (had never heard of it) that perfectly matches my requirement, but its not an easily available part.
    Friends please keep looking ....... am fast running out of choices. Would appreciate help very much.

    regards
    Anand
     
  11. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    The 4560 is a common Japanese audio dual opamp that is also made by New Japan Radio as a NJM4560. It has the same wide range of input offset voltage (max 6mV) as most other opamps. The Rohm BA4560 is the same.

    The TLE2141A dual opamp has a max supply of plus and minus 22V and a max input offset voltage of 1mV at room temperature.
     
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