Class AB output stage wih reduced distortion

An output stage of an amplifier circuit comprising:

• a sinking bipolar circuit for sinking current from an external load;
• a sourcing transistor for sourcing current to the external load, the sourcing transistor coupled in series with the sinking bipolar circuit, a common output node is formed between the sourcing transistor and the sinking bipolar circuit;
• a mirroring transistor coupled to the sourcing transistor such that current in the sourcing transistor approximately mirrors current in the mirroring transistor;
• a current mirror circuit responsive to the mirroring transistor and coupled to control current flow through the sinking bipolar circuit;
• and
• a translinear bias circuit coupled to the sinking bipolar circuit for maintaining a minimum current in the bipolar circuit, the translinear bias circuit comprises a first bipolar transistor, a second bipolar transistor having a base and collector coupled to an emitter of the first bipolar transistor, a third bipolar transistor having a base and collector coupled to an emitter of the second bipolar transistor, and a fourth bipolar transistor having a base coupled to a base and collector of the first transistor and having an emitter coupled to the sinking bipolar circuit.