Amplifier Question

Discussion in 'General Electronics Chat' started by Tom88, Oct 18, 2011.

  1. Tom88

    Thread Starter New Member

    Oct 14, 2011
    4
    0
    I got a question about amplifiers and noise. Does a inverting amplifier add more noise than a non inverting amplifier? My rails are +5V and -5V. The +5V has about 1mV or noise and the -5V has 2mv of noise.
     
  2. Veracohr

    Well-Known Member

    Jan 3, 2011
    552
    76
    Inverting/non-inverting amplifier type depends on the input/feedback configuration, not the power supplies.
     
  3. #12

    Expert

    Nov 30, 2010
    16,343
    6,827
    True. An op-amp, or any other well designed amp, will reject power supply ripple and noise by virtue of the configuration of the transistors.

    For really nit-picking noise calculations, the input and feedback resistors are usually the major noise source.
     
  4. crutschow

    Expert

    Mar 14, 2008
    13,050
    3,244
    The intrinsic op amp input noise gain is amplified by the non-inverting gain or 1 + the inverting gain. Thus for a gain of 1 the inverting amp will have twice the noise gain for the op amp intrinsic input noise as the NI amp.
    Edit: This is for the op amp input noise (in V/√Hz as given in the data sheet).
     
    #12 likes this.
Loading...