Low Phase Noise Technique for a Crystal Oscillator Circuit

摘要

In aspects of a low phase noise technique for use with a crystal oscillator, a bias control circuit sets a bias voltage on the gate of a first transistor needed to sink or source an amount of current corresponding to a sensed common mode signal. The sensed common mode signal is sensed with a common mode sense circuit that is coupled across two ports of the crystal oscillator, and current is provided by a current source. The bias voltage is set by a bias controller that uses a second transistor coupled to the common mode sense circuit and the first transistor.