Variable gain differential current feedback amplifier

A new variable gain differential current feedback amplifier (CFA) is presented. In comparison to common CFA structures, the presented CFA provides several novelties, like symmetrical high impedance inputs, accurate and temperature stable gain, simple gain control without need of resistor feedback network and wide input dynamic range. Input offset is comparable to common voltage feedback amplifier (VFA) structures. All common CFA fruitful features, like gain independent band width (BW) are provided. A schematic implementation in 0.35 μm CMOS and measured results are shown.