Patent ID: 11936391
Assignee: TEXAS INSTRUMENTS INCORPORATED
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A phase-locked loop (PLL) comprising:
an input;
an output;
a phase frequency detector (PFD) having a first input coupled to the input of the PLL, having a second input, and having an output, the PFD operable to provide a first control signal in response to receiving and comparing a reference signal having a reference signal frequency to a feedback signal having a feedback signal frequency;
a first control circuit having an input coupled to the output of the PFD and having an output, the first control circuit operable to receive the first control signal and provide a second control signal having a current value determined based on the first control signal;
a second control circuit having an input coupled to the input of the PLL and having an output;
a modulation circuit having a first input coupled to the output of the first control circuit, having a second input coupled to the output of the second control circuit, and having an output, the modulation circuit operable to modulate the second control signal to provide a modulated control signal that varies in value within one period of the reference signal; and
an oscillator having an input coupled to the output the modulation circuit, having an output coupled to the second input of the PLL, the oscillator operable to provide a signal having an output frequency proportional to the value of the second control signal, wherein at a rising edge of the reference signal the second control signal has a value sufficient to cause the output frequency to equal the reference signal frequency.