Amplifier arrangement, e.g. for mobile radio receiver, has changeover device for selecting one of several resistances in feedback branches and/or cross-branch

摘要

The arrangement has a symmetrical operational amplifier (3) with a first input terminal pair (4) connected to the its input (1), a second input terminal pair (5) and an output terminal pair (6) connected to its output (2), feedback branches with resistances (7,8) between the output pair and second input pair, a cross-branch with a resistance (10) connecting both connections of the second input pair and a changeover device (9,12) for selecting one of several resistances in the branches.