op amp - does op amp exceed the source of voltage that i supply it

Discussion in 'General Electronics Chat' started by abu ali, Dec 15, 2015.

  1. abu ali

    Thread Starter New Member

    Dec 15, 2015
    2
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    does op amp exceed the source of voltage that i supply it
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    No. Most opamps cannot actually produce an output that even comes close to the power supply rails. Why do you ask?
     
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  3. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    Well standard op-amps can usually get fairly close, often within 15% or better. Rail-to-rail op-amps swing the output to the + or - supply voltage.

    But no, they cannot output more than they are given.
     
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  4. Picbuster

    Member

    Dec 2, 2013
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    Dear Abu Ali,

    @ allaboutcircuits ( this site) you will find

    Introduction to Operational Amplifiers

    Chapter 8 - Operational Amplifiers
    Please read first all documentation about a component before you ask.
    Two reasons;
    a: you learn and know how this thing is working.
    b:Other people whom like to help you are not wasting time to tell what you, with some effort, can find and read. If however this site is not fulfilling your need surf the internet and find the answers.
    When all that fails ask and we will, with great pleasure, help you.
     
  5. DickCappels

    Moderator

    Aug 21, 2008
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    abu ali, welcome to All About Circuits and thank you for participating.

    In spite of what @Picbuster posted above, there is no requirement that you first become and expert then exhaust all resources before asking questions here.
     
    spinnaker, JohnInTX, absf and 2 others like this.
  6. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    I find it interesting that you only have 37 posts but are already speaking for everyone here about something that is not even in the rules....
     
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  7. Papabravo

    Expert

    Feb 24, 2006
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    Some people learn better in a conversational, storytelling environment. I have no real problem with that.
     
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  8. Papabravo

    Expert

    Feb 24, 2006
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    Of course I am aware of opamps with such capabilities, but most analog beginners seem to be rat-chained to the venerable, if long-in-the-tooth, 741.
     
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  9. WBahn

    Moderator

    Mar 31, 2012
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    Are you asking if the output can exceed the voltage supply powering it? If so, that's been addressed.

    Are you asking if the input voltages can exceed the voltage supply power it? That depends on the opamp. Many (most?) run of the mill opamps have input voltage ranges that are narrower than the supply rails, but many have input voltage ranges that include the rails. Some even have input voltage ranges that exceed the rails by a noticeable amount (I've seen them, but I can't think of one off the top of my head -- my guess is that these are probably FET-input amps that have the input protection circuits modified). The data sheets usually make a big deal of pointing these out.
     
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  10. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    Sorry @Papabravo, I meant no offense. I was sure you were aware of them, but I figured for completeness sake I should mention rail-to-rail op-amps, in case the OP or young future readers came along who might misunderstand your post.

    Regards,
    Matt
     
  11. Papabravo

    Expert

    Feb 24, 2006
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    I took no offense and was merely trying to reflect lack of performance in early devices that are so beloved by the academic community.
     
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  12. Whatashame

    Member

    Nov 30, 2015
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    Thank you for that. Sometimes one maybe working on some project and needs help right now. We may not have time to search all of AACs post and search the internet. When I search for answers I get lost and then forget what I asked. I never need a long song and dance, just tell me want I need or what parts will do the trick. I like your answer. Most answers sound like Japenness, hard to understand as a "lay" person. Excuse me, Japan.
     
    absf likes this.
  13. Whatashame

    Member

    Nov 30, 2015
    83
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    He may have only 37 posts, but I was told the same thing. It doesn't make sense. I'm pretty sure most biggener's questions have been asked and discussed many times. So if your not allowed to ask questions that have been asked unless you do all kinds of search ing first, then this site should be an information site only, and no questions allowed. I got scream at a couple of times for asking something or adding to the site. Again, to be clear, as new people, we are asked to read everything first before participating. I think he was just passing that on and meant nothing otherwise. I like what you posted.
     
  14. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Depends on the forum. Over in homework there is a fairly stiff rule (and rightly so) about not just giving out answers without the OP showing that they did some work on their own. In chat and projects things are much more flexible, but still we appreciate a question that shows a little effort.

    And don't be banging on the 741. Guitar effects people love those critters.

    ak
     
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  15. Papabravo

    Expert

    Feb 24, 2006
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    As long as you understand their limitations you can keep using them till the cows come home.
     
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  16. Whatashame

    Member

    Nov 30, 2015
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    Well that was nicely said and helpful. I will stay away from the "Homework" forum. I do read my electronic books over and over. I'm a type person that learns fast once I see the actual part needed and how it is used. I search for answers and otherwise gets nothing done. You should see all the parts I have and I still don't know how to use them. Then I buy more because I m always missing one or there is a term I don't under stand. I did get my Arduino Nano programed to make the light blink, but anything else goes to error. That will probably take me 2 years to straight en out. Lol. Thank you for your kind information about this site. Sometimes I think it is a cliquic like in high school. Your either in, or your out. Excuse my spelling.
     
    Last edited: Dec 15, 2015
  17. wayneh

    Expert

    Sep 9, 2010
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    It's not that bad. Every once in a while, one of us humans will reach a tipping point and unload on a random passerby. I know I have. That one person then receives the accumulated aggravation built up from the ten before him. When you've been here a while and seen some crazy requests for yourself, you'll see why it takes great patience. It wouldn't surprise me if half or more of the posts in this forum are to ask basic questions of the thread starter, so that we can understand what they are doing or what they want. It grows old.
     
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  18. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    There is nothing harder to compose, or easier to answer, than a well-formed question.

    ak
     
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  19. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    Only if it's a magical op-amp.

    There IS a way of getting more voltage out of an op-amp than you put in, using method called Charge pumping, but this is pretty exotic technology. In general, don't expect to get more than about 90% of the rail voltage on your output signal.
     
  20. Whatashame

    Member

    Nov 30, 2015
    83
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    Well see, your a good guy for taking the time to explain. Yes, nobody wants to step on your feet or waste your time. I can understand that. Now we know. I use to teach new apprentice s how to do electrical work, what each part is called and where to find it in the truck. I does get old. I try to laugh at this now, not laughing at anyone but at the situation. Here we go again, right? I do have to make clear, all the help and answers you and everyone gives on this site is very commendable. You are sharing n giving of yourselves. That is what the world needs, more people like you. Sharing your knowledge is far better than throwing money at people. Your giving us a gift. Thanks. What-a-shame out.
     
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