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US 9,287,825 B2Granted
Inductive-capacitive (LC) voltage controlled oscillator (VCO) having tuning range controlled by a digital-to-analog converter (DAC) with programmable tail current
AssigneeAvago Technologies General IP (Singapore) Pte. Ltd.
InventorAli Atesoglu
Life of this patent
Estimating the term…
Abstract
A device includes an inductive-capacitive voltage controlled oscillator (LC-VCO) having a tank circuit and programmable tail current, and a control circuit configured to adjust the tail current based on an amount of capacitance provided to the tank circuit.
Claims18
A device, comprising:
- a programmable digital-to-analog converter configured to generate a tail current;
- an inductive-capacitive voltage controlled oscillator (LC-VCO) having a tank circuit, the tank circuit comprising:
- a center-tapped inductor configured to receive the tail current from the programmable digital-to-analog converter;
- and
- a pair of voltage-controlled capacitors coupled in parallel with the center-tapped inductor, the pair of voltage-controlled capacitors having a control voltage coupled into a node between the pair of voltage-controlled capacitors for fine tuning the tank circuit;
- and
- a control circuit configured to provide to the programmable digital-to-analog converter a digital control signal for adjusting the tail current, wherein the digital control signal is based on an output of the LC-VCO.
4 more elements
A method, comprising:
- using a programmable digital-to-analog converter to generate a tail current;
- generating an oscillation frequency in an inductive-capacitive voltage controlled oscillator (LC-VCO) by providing the tail current to a center-tapped inductor of a tank circuit;
- fine tuning the tank circuit by varying a control voltage that is provided at a node between a pair of voltage-controlled capacitors connected in parallel with the center-tapped inductor;
- and
- adjusting the tail current based on an amount of capacitance that is coupled to an output of the LC-VCO.
2 more elements
A device, comprising:
- an inductive-capacitive voltage controlled oscillator (LC-VCO) having a tank circuit, the tank circuit comprising:
- a center-tapped inductor that is provided a tail current;
- and
- a pair of voltage-controlled capacitors coupled in parallel with the center-tapped inductor, the pair of voltage-controlled capacitors having a control voltage coupled into a node between the pair of voltage-controlled capacitors for fine tuning the tank circuit;
- a switchable capacitive network coupled to an output of the tank circuit for coarse tuning the tank circuit;
- and
- a programmable digital-to-analog converter configured to generate the tail current in accordance with the coarse tuning of the tank circuit.
4 more elements
Dependencies are inferred from the claim text.