Patent Number: 6,294,958

Title: Apparatus and method for a class AB output stage having a stable quiescent current and improved cross over behavior

Abstract: An electronic circuit for a Class AB output stage that has a differential input and a single ended output. A pair of clamp transistors are coupled between the bases of a pair of output transistors so that cross-over distortion is reduced and the output transistors do not completely turn off. A floating current source is employed to provide a stable quiescent current over a range of supply voltages. Also, the types and sizes of the transistors in the floating current source and the clamp transistors are matched so that any non-linear change in the operation of the clamp transistors caused by the Early effect over a range of supply voltages is automatically compensated for.

Inventors: Eschauzier; Rudolphe Gustave Hubertus (Bergschenhoek, NL)

Assignee: National Semiconductor Corporation

International Classification: H03F 3/30 (20060101); H03F 1/32 (20060101); H03F 003/26 ()

Expiration Date: 09/25/2018