suggest me a suitable op-amp

Discussion in 'The Projects Forum' started by pratapkollu, Jul 12, 2007.

  1. pratapkollu

    Thread Starter Active Member

    Dec 13, 2006
    respected members
    I need an op-amp that is active even after 100KHz(in frequency Vs Vom-maximum peak output voltage graph), I need output voltage between the range of 100 to 200khz. Please see the atached figure. presently i am using TL082, but its inefficient. Please suggest me suitable op-amp(preferably like TL082, same pin configuration). This is because I have already made PCB using TLO82 op-amp.
    Thanks and Regards
  2. thingmaker3

    Retired Moderator

    May 16, 2005
  3. pratapkollu

    Thread Starter Active Member

    Dec 13, 2006
  4. Papabravo


    Feb 24, 2006
    When you say the TL082 is inefficient, what does that mean exactly. Linear circuits, like class A amplifiers, are often inefficient. What supply voltage are you using?
  5. cumesoftware

    Senior Member

    Apr 27, 2007
    There are class AB amplifiers like the TDA2003, but I don't know if it is suitable for you. I'll finish a project using this particular amp soon.
  6. nanovate

    Distinguished Member

    May 7, 2007
    For your circuit you need a gain of 20 at 100KHz so you need an opamp that has plenty of gain left at 100KHz -- I recommend an opamp with 10 MHz GBWP minimum. This would leave plenty of open loop gain. Maybe there is something like the TLC082 from TI. It won't work for your design-- close but it is single ended with max supply of only 16V. I will take a look around though and maybe I can find one that'll work. It has become harder to find fast opamps that are "high" voltage and are in DIP.

    The TL082 is a dual opamp, are you using both?

    I am not sure what you mean by that. Are you referring to the fact that it is not a R-R output and so you need to use +/-15V supply to get a +/-12V swing? Or do you mean that it has a high power consumption?
  7. Distort10n

    Active Member

    Dec 25, 2006
    Simply picking an amplifier with 10 MHz GBWP will not help. It is not just a function of gain bandwidth, but also slew rate. Case and point, the OPA228; it has 33 MHz of GBW. If his input peak voltage was 500mV, then he would expect slew rate induced distortion roughly around 160 kHz.

    FPBW (full power bandwidth) is a function of slew rate, signal gain, and input peak voltage:

    FPBW = SR/(2*pi*Av*Vpeak-in)

    The OPA2228 should work since his peak input voltage is only 250mV. That should give him roughly 320 kHz of bandwidth. It will also serve a 20Vp-p output swing on a +/-15V supply, assuming no load conditions.
  8. nomurphy

    AAC Fanatic!

    Aug 8, 2005
    Try Linear Technology -- LT1211 in a DIP pkg.
  9. pratapkollu

    Thread Starter Active Member

    Dec 13, 2006
    thank you all, for valuble suggestions