Switchable gain amplifier with frequency compensation network - has individual compensation circuits which act independently on each of amplifiers pass bands for its N gains

摘要

The multiple gain switchable amplifier has a high impedance input, having a differential amplifier circuit and n differential input stage fed through an input stage selector. Each input stage has two outputs connected to the inputs of the amplifier circuit, in which each differential input stage has respectively applied an analogue input signal and the output signal of the amplifier circuit through a resistive network, so as to give to the amplifier a gain value among n possible values. The amplifier has also a frequency compensation circuit composed of individual compensation circuits (R1C1, R2C2) respectively mounted between the outputs of at least the input stages (6, 7), giving to the amplifier the lowet gain values. The compensation circuits are also connected to the inputs of the amplifier through means (d1 d'1, d2 d'2) controlled by the corresponding input stage, so as to independently connect them to the amplifier circuits inputs or to isolate them from these inputs.