Am improved tail current source for low voltage applications

A new current source for low-voltage applications is proposed. This current source is well suited for biasing differential pairs and source followers. Measured compliance voltage is slightly smaller than that of a single transistor. Its output resistance is a factor of 25 larger than that of a single transistor current source and was measured to be 8 M/spl Omega/. The use of the new current source improves the common-mode input range and the common-mode rejection ratio of fully balanced and single-ended differential amplifiers.