DIFFERENTIAL AMPLIFIER WITH INPUT STAGE INVERTING COMMON-MODE SIGNALS

摘要

To eliminate common-mode components in differential input signals without the necessity of introducing a transformer and a special feedback loop for eliminating common-mode components, a differential amplifier (1) comprises a first input stage (11) for receiving differential input signals comprising common-mode signals and for outputting first differential intermediate signals, a second input stage (12) for inverting the common-mode signals and for combining inverted common-mode signals and the first differential intermediate signals into second differential intermediate signals, and an output stage (13) for receiving the second differential intermediate signals and for outputting differential output signals. The first input stage (11) comprises a folded cascode stage with first and second transistors (31,32), the second input stage (12) comprises a mirror stage with third, fourth, fifth, sixth and seventh transistors (33,34,35,36,37), and the output stage (13) comprises a common main electrode stage with tenth and eleventh transistors (40,41).