Amplifier resistor values

Discussion in 'General Electronics Chat' started by Blackbull, May 25, 2010.

  1. Blackbull

    Thread Starter Well-Known Member

    Jul 26, 2008
    Hi Folks,
    I trust that the experts here will not require a schematic for an inverting amplifier where the gain is configured by the division of resistor 2 by resistor 1. There isn’t much said about the values of these resistors, I gather that they should be high, but what is permissible say for a gain of 10: 100k/10k, 10k/1k or 10/1 ohms?
    Many thanks, Blackbull
  2. Norfindel

    Active Member

    Mar 6, 2008
    It's an operational amplifier? If it is, you can set the lower resistor to 1k in most cases. IIRC, going too high can cause problems with noise, but Application Notes can shed some light about what are the limits for a specific amplifier.
    Blackbull likes this.
  3. Audioguru

    New Member

    Dec 20, 2007
    Most opamps have a max output current of only 20mA. At such a "high" current their output voltage loss is high. A few opamps can drive a load as low as 600 ohms with a fairly high peak voltage.
    Blackbull likes this.