op amp

Discussion in 'General Electronics Chat' started by soudabeh, Jul 30, 2011.

  1. soudabeh

    Thread Starter New Member

    Jul 4, 2011
    I'm looking for an op amp which frequency bandwidth is higher than 4Mhz & its gain is selectable (from 5 to 20).plaese help me.
    thanks in advance......
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    there are so many of them. a simple search in digikey gives more than 2000 items.

    - open www.digikey.com
    - type "opamp" in the search field
    - click on Linear - Amplifiers -Instrumentation, OP Amps, Buffer Amps
    - press and hold Ctrl and select all frequencies higher than 4MHz under "Bandwith"
    - click "Apply"
    soudabeh likes this.
  3. SgtWookie


    Jul 17, 2007
    Well, there are lots of opamps with GBW > 4MHz.
    How about an LM6132 or MC33078?

    As far as selectable gain, all you'd need to do is use a selectable feedback network to get the gain you wanted, like this:


    Note that 90k is not a standard value of resistance, but you can use a 68k and 22k in series, or two 180k resistors in parallel to get 90k Ohms. Or you could use all 30k Ohm resistors; two in parallel to get 15k, and three in series to get 90k.
    soudabeh likes this.
  4. Ron H

    AAC Fanatic!

    Apr 14, 2005
    S1 and S2 labels need to be swapped, like this:
    Last edited: Jul 31, 2011