Operational amplifier with high slew rate

Abstract

An operational amplifier (2) comprises a first differential stage (3) for receiving first (IP) and second (IM) input signals and for providing first (OP) and second (OM) output signals at first and second output nodes, and second (4) and third (6) differential stages, which are each coupled to receive the first (IP) and second (IM) input signals and to the first and second output nodes to provide first and second additional signals thereto. Each stage comprises two transistors (22, 24 and 32, 34) differentially connected. One of the transistors of each stage has a greater transconductance than the other, whereby for small input signals the first and second additional signals are negligible and for large input signals when the input signals difference is positive, the second differential stage (4) adds first and second additional signals to the first (OP) and second (OM) output signals respectively and when the input signals difference is negative, the third differential stage (6) adds first and second additional signals to the first (OP) and second (OM) output signals respectively.

Dependencies are inferred from the claim text.