Differential transconductance stage, dynamically controlled by the input signal's amplitude.

摘要

The dynamic range of operation of a transconductance differential input stage is reduced when the amplitude of the input signal decreases, thus reducing the level of the noise that is generated by the input stage. A DC signal representaive of the sensed amplitude of the input signal is employed for either reducing the value of a common, emitter-degenerating resistance (R) or of the bias current that is forced in the two branches of the differential input stage. <IMAGE>