Abstract text

An amplifier circuit has an amplifier stage (10), comprising an amplifier transistor (104) with a gate coupled to an input (100) of the amplifier stage (10), a source coupled to a reference connection (gnd) and a drain coupled to a positive power supply connection (V+). A bias stage (12) is provided comprising a bias transistor (120), a drain resistance (124) and a source resistance (122), the bias transistor (120) having a gate coupled to a negative power supply connection (V−), a source coupled to the negative power supply connection (V−) via the source resistance (122) and a drain coupled to the reference connection (gnd) via the drain resistance (124) and to the gate of the amplifier transistor (104). The bias stage comprises a further resistance (20, 22), coupled from a node between the source of the bias transistor and the source resistance of the bias transistor (120) to a circuit node that carries a voltage higher than the voltage at the negative power supply connection.