A dynamic range boosted, low-power method adding continuous variable gain to amplifiers

A low-power method increasing the adjustable gain range of continuous variable gain amplifiers is presented. The method is an improvement of an architecture using continuous adjustable feedback in parallel with a fixed feedback path. This previous presented architecture suffers from the fact that high attenuation levels require dramatic increase in additional power consumption. The proposed method described in this paper avoids such a severe increase in power at higher attenuation levels. The method is based on the idea of introducing additional feedback in the gain controlling-loop of the already present additional, adjustable feedback path that continuously controls the gain. The nominal gain of 20dB at 3MHz of the core amplifier is continuously adjusted down to 0dB. The estimated additional power consumption is 1mW.