Lab 4

Lab  4   Positive and Negative Feedback with Operational Ampliefiers  

4A  Positive feedback: Schmitt Trigger Comparator 
      I.   Comparator (with no feedback)  

     II.  Comparator with positive feedback: Schmitt trigger

4B   Negative feedback :     The golden rules of an Operational Amplifier

                                                          Amplifiers circuits, Transfer function, Active low pass filters
I. Purpose
II.   THEORETICAL CONSIDERATIONS
  II.1   Negative feedback

    II.2   Operational Amplifiers with “Infinite” and Finite Gain

              II.2.A    The concept of open loop gain and close loop gain

              II.2.B    Op-amps with infinite open loop gain:

                       The Golden Rules of Operational Amplifiers

III.  EXPERIMENTAL CONSIDERATIONS

    Applications of negative feedback with operational amplifiers

    III.1  Amplifiers Circuits (Only this section is required in 2023)

               III.1.A  The Inverting Amplifier

                              f3dB frequency (test  in the frequency domain)

                              Slew-rate (test in the time domain)

                              Transfer function (analysis in the Laplace domain)

              III.1.B   The Noninverting Amplifier

              III.1.C   The differential

              III.1.D   The Integrator

              III.1.E      Differentiator

    III.2  Active Filters (Not required in 2023)

              III.2.A   Exploiting the low output impedance and high input impedance of op-amps

              III.2.B   Active pass filters: Filters with steeper roll-off