Patent ID: 6593814
Filing Date: 2003-07-15
Classification: H03F

Abstract:
An amplifier circuit, comprising:a reference-ground potential terminal; an amplifier stage having an input for receiving a signal to be amplified, an output at which an amplified signal can be drawn off, and a reference node; an in-phase regulator having an input side for receiving a regulating voltage, a load side having a first end connected to said reference node and a second end connected to the reference-ground potential terminal, said in-phase regulator reducing a DC voltage dropped across said amplifier stage between said output and said reference node; said in-phase regulator having a controllable resistor controlled by the regulating voltage, said controllable resistor having a first end connected to said reference node on said load side, a second end connected to said reference-ground potential terminal, and a control input; said in-phase regulator further having a regulating loop containing an operational amplifier having an inverting input receiving the regulating voltage, a non-inverting input connected to said reference node, and an output coupled to said control input of said controllable resistor for controlling said controllable resistor; and a voltage regulator having a supply potential terminal for receiving a supply potential and an output outputting the regulating voltage received by said in-phase regulator, the regulating voltage having a fixed potential difference with respect to the supply potential.