Patent ID: 6222417
Filing Date: 2001-04-24
Classification: H03F

Abstract:
An amplifier output stage comprising a first and a second transistor each provided with a bias terminal, a reference terminal and a transfer terminal, said transistors having their main current paths arranged between a first and a second power supply terminal, a junction point between said current paths constituting an output terminal of the stage, the bias terminal of the first transistor being connected to an output of the amplifier, and the bias terminal of the second transistor being connected to an input of the amplifier via a bias circuit, characterized in that the bias circuit includes means for limiting a bias current only when the second transistor is saturated, which comprises:a detection module for providing an electrical signal at the instant when the second transistor enters the state of saturation, andan impedance matching module including at least one transistor for generating a high impedance at the bias terminal of the second transistor only when said transistor becomes saturated.