Environmental Engineering Reference
In-Depth Information
and is equivalent to (6.37).
The
ideal
shunt-shunt feedback amplifier is depicted in Fig. 6.28. It
performs the current to voltage conversion thanks to the virtual ground
exhibited by the differential amplifier. Its transfer function is
The
ideal
series-series feedback amplifier is shown in Fig. 6.29. It
performs a voltage to current conversion. Indeed, due to the virtual short
circuit, the input voltage appears at the inverting node of the differential
amplifier, thus generating a current through resistance, which is also
equal to that through resistance, The differential amplifier output voltage
is then set by and the current through This, divided by sets the
differential amplifier output current,
i
, that is replicated at the output of the
series-series feedback amplifier through the current-controlled crrent source
of gain The ideal transfer function of the series-series feedback amplifier
is hence given by
