Transfer function derivation of some circuits.
Writing down the nodal equations of various Operational amplifier circuits, and
then deriving the output, seems to be a bit quicker than fumbling around with
currents . Did all these in part of one morning. The 'output current being
independant of load' proof, for some reason wasn't able to do whilst at
University (Keele, UK: Electronics, no longer a mainstream subject here, think
!). Also have had to leave the calculations in their original form, as it really
is too much trouble to try to convert it all into HTML Some of these you will
find in textbooks, with the author completely omitting how the calculation is
done. One current textbook, specifically for Op-Amps, was found to be riddled
with stupid mistakes. It won't be mentioned, to save further embarrassing the
Authors, who should have done a better job of proof-reading their work. In most
feedback configurations, both inputs will be driven to the same potential
(Virtual Earth). Va is the reference voltage used in most of these examples.
Its elegant, the way various terms cancel out, (especially the 1st and 2nd order
Group Delay equalisers), to leave a fairly simple equation.
The first two are the standard inverting and non-inverting configurations.
Inverting Configuration
Non-Inverting Configuration
Differential Amp
Proof that IL is independant of load Z. Question of class test in part of
Electronics Degree.
Transfer function of First Order Group Delay Equaliser.
This and the next, use complex s frequency operator. This particular one is a
complete proof, with rationalising and taking the modulus of the complex number
terms.
Transfer function of Second Order Group Delay Equaliser.
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