Finding gain with inverting amplifier

Discussion in 'Homework Help' started by uofmx12, Aug 24, 2011.

  1. uofmx12

    Thread Starter Member

    Mar 8, 2011
    Last edited: Aug 24, 2011
  2. JDT

    Well-Known Member

    Feb 12, 2009
    The section of the circuit from A to B is an attenuator (or voltage divider). It therefore has a gain of LESS than 1.

    The section of the circuit from B to D is an inverting amplifier. It will have a gain of MINUS(something).

    As this is the homework section, I will leave it to you to find out the formulas to work out the actual values.

    Note that point C is a "virtual earth" and has a potential very close to earth at all times. Therefore R1 is in parallel with Rb and this must be taken into account when calculation the gain of the attenuator section.

    The gain of the total circuit (from A to D) is the product of the gain of both sections. Gain(A-B) x Gain(B-D).