Patent ID: 6229403
Filing Date: 2001-05-08
Classification: H03K

Abstract:
A voltage-controlled oscillator comprising:a ring oscillator comprising a plurality of inverters that are connected in a ring-like arrangement;a voltage-current converter that controls an amount of current flowing through each of the inverters of said ring oscillator according to a voltage of an input signal;wherein said voltage-current converter comprises a first transistor (P101) that is connected to a power supply line and disposed such that current corresponding to the voltage of the input signal flows through the first transistor, each of the inverters of said ring oscillator having a second transistor (P103) that is connected to the power supply line and forms a current mirror circuit with the first transistor; andbiasing means for biasing said second transistor, said biasing means comprising a transistor having a device size thereof set to such a value relative to a device size of said first transistor and said second transistor such that the second transistor operates at a boundary between a saturation region and a non-saturation region.