US 12,255,663 B2
Dual-path phase locked loop (PLL) with closed-loop VCO temperature compensation
Masoud Moslehi Bajestan, San Diego, CA (US); Arpit Gupta, San Diego, CA (US); Wu-Hsin Chen, San Diego, CA (US); and Vinod Panikkath, San Diego, CA (US)
Assigned to QUALCOMM Incorporated, San Diego, CA (US)
Filed by QUALCOMM Incorporated, San Diego, CA (US)
Filed on Mar. 16, 2023, as Appl. No. 18/185,325.
Prior Publication US 2024/0313792 A1, Sep. 19, 2024
Int. Cl. H03L 7/099 (2006.01); H03L 1/02 (2006.01); H03L 7/087 (2006.01)
CPC H03L 7/0992 (2013.01) [H03L 1/021 (2013.01); H03L 7/087 (2013.01)] 24 Claims
OG exemplary drawing
 
1. 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.