Patent ID: 9577661
Date: 2017-02-21
CPC Classifications: G05F,H03F,H03K,H03M

Claim:
1. A voltage-controlled oscillator comprising: a voltage-current converter for receiving a first control voltage and a second control voltage and outputting a first output current proportional to the first control voltage and a second output current proportional to the second control voltage; a first ring oscillator including plural delay elements connected in a ring form and oscillating based on the first output current, which the voltage-current converter outputs in response to the first control voltage; and a second ring oscillator including plural delay elements connected in a ring form and oscillating based on the second output current, which the voltage-current converter outputs in response to the second control voltage, wherein the voltage-current converter includes: a first transistor for receiving the first control voltage at a gate terminal thereof; a second transistor for receiving the second control voltage at a gate terminal thereof; a third transistor connected to the first transistor in series and having a gate terminal connected to a drain terminal of the first transistor; a fourth transistor connected to the second transistor in series and having a gate terminal connected to a drain terminal of the second transistor; a resistor connected to a source terminal of the first transistor and a source terminal of the second transistor; a fifth transistor having a gate terminal connected to the drain terminal of the first transistor; and a sixth transistor having a gate terminal connected to the drain terminal of the second transistor.