Voltage controlled oscillator and phase locked loop including the same

摘要

A voltage controlled oscillator (VCO) includes an oscillation frequency signal generation circuit and a transconductance control circuit. The oscillation frequency signal generation circuit has a first transconductance and generates a first oscillation frequency signal and a second oscillation frequency signal based on a voltage control signal and a power supply voltage. The first and second oscillation frequency signals are a pair of differential signals. The oscillation frequency signal generation circuit is configured to output the first oscillation frequency signal from a first output node. The oscillation frequency signal generation circuit is configured to output the second oscillation frequency signal from a second output node. The transconductance control circuit is connected to the first and second output nodes and has a second transconductance. The transconductance control circuit is configured to adjust the second transconductance based on a digital control signal.

主权项

1. A voltage controlled oscillator (VCO) comprising:
an oscillation frequency signal generation circuit having a first transconductance, the oscillation frequency signal generation circuit configured to generate a first oscillation frequency signal and a second oscillation frequency signal based on a voltage control signal and a power supply voltage, the first and second oscillation frequency signals being a pair of differential signals, the oscillation frequency signal generation circuit configured to output the first oscillation frequency signal from a first output node, the oscillation frequency signal generation circuit configured to output the second oscillation frequency signal from a second output node; and a transconductance control circuit connected to the first and second output nodes, the transconductance control circuit having a second transconductance, and the transconductance control circuit configured to adjust the second transconductance based on a digital control signal, the VCO having a negative resistance based on the first transconductance and the second transconductance.