Environmental Engineering Reference
In-Depth Information
resistance, is small. The resultant closed-loop amplifier is therefore best
suited for voltage amplification, in the sense that the closed-loop voltage
gain can be made approximately independent of source and load resistances.
For large loop gain, this voltage loop gain is nominally determined by only
the feedback subcircuit parameters.
The small signal model of the amplifier in Fig. 6.1 is shown in Fig. 6.2,
where the model developed in section 2.4 and depicted in Fig. 2.7 has been
used for the degenerated common X transistor T2.
As a practical rule, evaluation of the terms needed both in the Rosenstark
and Choma methods or in the Blackman equations becomes simpler if one
