Patent ID: 7271655

Claim:
An end stage circuit for a push-pull power amplifier, the end stage circuit comprising: a first and a second power transistor connected in series, and a first and a second driver circuit coupled to respective control terminals of the power transistors, wherein the power transistors have a threshold voltage above which they are conductive and below which they are substantially non-conductive, wherein each driver circuit is arranged fcr receiving an input signal and for controlling the respective power transistor in response to said input signal, and wherein the driver circuits are arranged for causing the power transistors to cross their threshold voltage substantially simultaneously in respective opposite directions upon receipt of suitable input signals, and wherein the first driver circuit comprises a first driver transistor connected between a first auxiliary supply voltage and the control terminal of the first power transistor, and a second driver transistor connected between said control terminal and a main terminal of the first power transistor, and wherein the second driver circuit comprises a third driver transistor connected between a second auxiliary supply voltage and the control terminal of the second power transistor, and a fourth driver transistor connected between said control terminal and a main terminal of the second power transistor.