Phase locked loop for stably operating in a matter that is insensitive to variation in process, voltage and temperature and method of operating the same
First Claim
1. A Phase Locked Loop (PLL), comprising:
- a Phase Frequency Detector (PFD) for comparing a phase or frequency of a reference signal with a phase or frequency of an output signal and outputting an up signal or a down signal based on a comparison result;
a charge pump circuit for generating a pumping current in response to the up signal or the down signal and increasing or decreasing the pumping current in response to a detection signal;
a loop filter for outputting control voltage according to the pumping current;
a Voltage Controlled Oscillator (VCO) for outputting the output signal having a frequency determined based on the control voltage; and
a peak voltage detector for detecting a peak value of the control voltage and outputting the detection signal based on a detection result.
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Abstract
A phase locked loop for stably operating in a matter that is insensitive to variation in PVT and a method of operating the same. The PLL according to the present invention includes a PFD, a charge pump circuit, a loop filter, a VCO, and a peak voltage detector. The PFD compares a phase or frequency of a reference signal with a phase or frequency of an output signal and outputs an up signal or a down signal based on the comparison result. The charge pump circuit generates a pumping current in response to the up signal or the down signal and increases or decreases the pumping current in response to a detection signal. The loop filter outputs control voltage according to the pumping current. The VCO outputs the output signal having a frequency determined based on the control voltage. The peak voltage detector detects the peak value of the control voltage and outputs the detection signal based on the detection result. The PLL detects the peak value of control voltage and controls the operation of a charge pump circuit based on the detection result thereby decreasing the peaking and ringing phenomena of the control voltage and then stably operating in a manner that is insensitive to variation in PVT.
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Citations
29 Claims
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1. A Phase Locked Loop (PLL), comprising:
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a Phase Frequency Detector (PFD) for comparing a phase or frequency of a reference signal with a phase or frequency of an output signal and outputting an up signal or a down signal based on a comparison result;
a charge pump circuit for generating a pumping current in response to the up signal or the down signal and increasing or decreasing the pumping current in response to a detection signal;
a loop filter for outputting control voltage according to the pumping current;
a Voltage Controlled Oscillator (VCO) for outputting the output signal having a frequency determined based on the control voltage; and
a peak voltage detector for detecting a peak value of the control voltage and outputting the detection signal based on a detection result. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A Phase Locked Loop (PLL), comprising:
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a PFD for comparing a phase or frequency of a reference signal with a phase or frequency of a divided signal and outputting an up signal or a down signal based on a comparison result;
a charge pump circuit for generating a pumping current in response to the up signal or the down signal and increasing or decreasing the pumping current in response to a detection signal;
a loop filter for outputting control voltage according to the pumping current;
a VCO for outputting the output signal having a frequency determined based on the control voltage;
a divider for dividing the output signal in a predetermined division ratio and outputting the divided signal; and
a peak voltage detector for detecting a peak value of the control voltage and outputting the detection signal based on a detection result. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A method of operating a PLL for generating an output signal in synchronous with a reference signal, comprising:
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comparing a phase or frequency of a reference signal with a phase or frequency of an output signal and outputting an up signal or a down signal based on a comparison result;
generating a pumping current in response to the up signal or the down signal and increasing or decreasing the pumping current in response to a detection signal;
outputting control voltage according to the pumping current;
adjusting the frequency of the output signal according to the control voltage;
detecting a peak value of the control voltage and outputting the detection signal based on a detection result; and
adjusting an amount of the pumping current in response to the detection signal. - View Dependent Claims (28, 29)
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Specification