op-amp for low Vin, beginner

Discussion in 'The Projects Forum' started by ASDF_, Sep 22, 2010.

  1. ASDF_

    Thread Starter New Member

    Sep 10, 2010
    Hi guys

    I am completely new in electronic design, still I have to desing an op-amp.
    I want to amplify an AC signal that has a very low amplitude (about 1mV peak-peak). how can I get this done? I have to use the noninverting ac amplifier configuration. The width of the pulses that I have to amplify is about 3us

    So my main problem (i guess) is which op-amp to use, I mean which IC
    and then resistors and capacitors

    Thank you in advance

    P.S sorry for my english but it's not my mother tung
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    That's not a particularly high frequency(less than 1 MHz) so most any modern opamp would function. 1 mV is rather small for a signal level, so you might have to worry about noise. For a first circuit I would ignore that possibility and just work on getting an amp design. Do you have a circuit simulator like spice? I'm keen on that, since I'm learning how to use it vs. breadboarding. It makes substituting components stupidly fast. :)

    What amplitude output do you need. Single rail supply or dual? Dc component on the input?

    Flesh out your needs a little more, and in the process of giving US the info, you will get a better idea of what YOU need to do.
  3. ASDF_

    Thread Starter New Member

    Sep 10, 2010
    thanks for the quick reply!!

    The output amplitude is not of great importance, it could be around 0.01 to 0.1mV or more.
    I guess it should be dual rail supply as its AC signal
    I forgot to mention that the input signal is coming from a search coil of a sensor and the output will be connected to an oscilloscope

    I from what I read I should get a zero input offset voltage amp, cos of the small input voltage?
    Last edited: Sep 22, 2010