Common-mode controlled differential gain boosting

摘要

A current source circuit with common-mode differential gain boosting is provided. The current source circuit differentially provides first and second currents. The first current is produced by a first cascoded current source, and the second current is produced by a second cascoded current source. Each of the cascoded current sources comprises a current source transistor and a cascode transistor. The current source circuit has high output impedance utilizing gain-boosting techniques. A three-input differential amplifier forces a gate of the cascode transistor of each of the current source circuits to an approximately constant voltage. The three-input differential amplifier is configured to receive a bias signal. The current source circuit is arranged to servo both the gate and source of the cascode transistors in response to the bias signal.