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US 12,255,663 B2Granted
Dual-path phase locked loop (PLL) with closed-loop VCO temperature compensation
AssigneeQUALCOMM Incorporated
InventorsMasoud Moslehi Bajestan, Arpit Gupta, Wu-Hsin Chen, Vinod Panikkath
Life of this patent
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Abstract
In certain aspects, a system includes a voltage-controlled oscillator (VCO), a phase detector configured to receive a reference signal, a frequency divider coupled between an output of the VCO and the phase detector, a phase-to-current circuit coupled to an output of the phase detector, and a temperature circuit configured to output a temperature-dependent voltage. The system also includes a switching circuit configured to selectively couple the phase-to-current circuit to an input of the VCO and configured to selectively couple the temperature circuit to the input of the VCO.
Claims24
A system comprising:
- a voltage-controlled oscillator (VCO) having a first input, a second input, a third input, and an output;
- a phase detector having a first input, a second input, and an output, wherein the first input of the phase detector is configured to receive a reference signal;
- a frequency divider coupled between the output of the VCO and the second input of the phase detector;
- a phase-to-voltage circuit coupled to the output of the phase detector, wherein the phase-to-voltage circuit is configured to generate a first voltage and a second voltage based on a phase signal from the phase detector, output the first voltage at a first output of the phase-to-voltage circuit, and output the second voltage at a second output of the phase-to-voltage circuit;
- a transconductance amplifier configured to generate a current based on the first voltage and the second voltage, and provide the current at an output of the transconductance amplifier;
- a first path coupled between the first output of the phase-to-voltage circuit and the second input of the VCO;
- a second path coupled between the second output of the phase-to-voltage circuit and the third input of the VCO;
- a temperature circuit having an output, wherein the temperature circuit is configured to output a temperature-dependent voltage at the output of the temperature circuit;
- a switching circuit having a first terminal, a second terminal, and a third terminal, wherein the first terminal is coupled to the output of the transconductance amplifier, the second terminal is coupled to the output of the temperature circuit, and the third terminal is coupled to the first input of the VCO;
- and
- a capacitor coupled to the first input of the VCO.
8 more elements
A system comprising:
- a voltage-controlled oscillator (VCO) having an input and an output;
- a phase detector having a first input, a second input, and an output, wherein the first input of the phase detector is configured to receive a reference signal;
- a frequency divider coupled between the output of the VCO and the second input of the phase detector;
- a phase-to-current circuit having an input and an output, wherein the input of the phase-to-current circuit is coupled to the output of the phase detector;
- a temperature circuit having an output, wherein the temperature circuit is configured to output a temperature-dependent voltage at the output of the temperature circuit, and wherein the temperature circuit comprises:
- a first current source configured to generate a first current that is temperature dependent;
- a resistor coupled to the first current source;
- and
- a buffer having an input and an output, wherein the output of the buffer is coupled to the output of the temperature circuit, and the input of the buffer is coupled between the first current source and the resistor;
- a switching circuit having a first terminal, a second terminal, and a third terminal, wherein the first terminal is coupled to the output of the phase-to-current circuit, the second terminal is coupled to the output of the temperature circuit, and the third terminal is coupled to the input of the VCO;
- and
- a capacitor coupled to the input of the VCO.
9 more elements
A system comprising:
- a voltage-controlled oscillator (VCO) having a first input, a second input, and an output;
- a phase detector having a first input, a second input, and an output, wherein the first input of the phase detector is configured to receive a reference signal;
- a frequency divider coupled between the output of the VCO and the second input of the phase detector;
- a temperature circuit having an output, wherein the temperature circuit is configured to output a temperature-dependent voltage at the output of the temperature circuit;
- a first charge pump having an input coupled to the output of the phase detector;
- a second charge pump having an input coupled to the output of the phase detector and an output coupled to the second input of the VCO;
- a switching circuit having a first terminal, a second terminal, and a third terminal, wherein the first terminal is coupled to an output of the first charge pump, the second terminal is coupled to the output of the temperature circuit, and the third terminal is coupled to the first input of the VCO;
- and
- a capacitor coupled to the first input of the VCO.
6 more elements
A system comprising:
- a voltage-controlled oscillator (VCO);
- a phase detector configured to receive a reference signal;
- a frequency divider coupled between an output of the VCO and the phase detector;
- a phase-to-voltage circuit coupled to an output of the phase detector;
- a transconductance device coupled to a first output and a second output of the phase-to-voltage circuit;
- a temperature circuit configured to output a temperature-dependent voltage;
- a switching circuit configured to selectively couple the transconductance device to a first input of the VCO and configured to selectively couple the temperature circuit to the first input of the VCO;
- a first path coupled between the first output of the phase-to-voltage circuit and a second input of the VCO;
- and
- a second path coupled between the second output of the phase-to-voltage circuit and a third input of the VCO.
7 more elements
Dependencies are inferred from the claim text.