Patent ID: 7084706

Claim:
A circuit arrangement comprising: an amplifier including a first bipolar transistor having a base terminal, wherein the base terminal of the first bipolar transistor is connected to an input terminal for a signal to be amplified; a biasing circuit operable to set a potential at the base terminal of the first bipolar transistor, the biasing circuit comprising a second bipolar transistor including a base terminal, a reference current source and resistors, wherein the base terminals of the first and second bipolar transistors are connected to the reference current source across the resistors, wherein the first and second bipolar transistors are connected such that a potential change occurs faster at the base terminal of the second bipolar transistor than at the base terminal of the first bipolar transistor in response to switching on or off the reference current source; an additional source configured to provide a current to the base terminal of the first bipolar transistor; a detector operable to detect a potential difference between the potentials at the base terminals of the first and second bipolar transistors in order to detect whether the first bipolar transistor is to be switched by switching on or off the reference current source; and a connector operable to connect the additional source to the base of the bipolar transistor when the first bipolar transistor is to be switched.