System including circuitry for controlling a characteristic of a periodic signal and method for adjusting a signal
First Claim
1. Phase locked loop circuitry comprising:
- a voltage controlled oscillator, for adjusting phase or frequency characteristics of an output signal, having a first input terminal and an output terminal on which the output signal is provided;
a phase and frequency detector which generates analog VCO input signals indicative of a phase difference or a frequency difference between the VCO output signal and a reference signal;
conversion circuitry coupled to translate the analog VCO input signals from an analog form into digital versions to adjust the VCO output signal;
signal driving circuitry, comprising a current source an output of which is a control signal generated by input of the digital version of the analog VCO input signals to the signal driving circuitry;
first input circuitry providing a first adjustment signal to the first input terminal of the VCO; and
second input circuitry providing a second adjustment signal to the first input terminal of the VCO in response to the control signal, wherein;
the first adjustment signal is based on input of the VCO input signals in the analog form to a circuit element in the first input circuitry to control the first adjustment signal; and
the control signal, to which the second input circuitry is responsive to provide the second adjustment signal, is determined with the digital versions of the VCO input signals.
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Accused Products
Abstract
System and circuitry controlling characteristics of periodic signals. In one embodiment adjustment circuitry modifies periodic signal characteristic. A phase detector generates analog input signals indicative of a phase difference between the periodic signal and a reference signal. Conversion circuitry translates the analog input signals into digital signals. Signal driving circuitry, comprising a current source, provides control signals to the signal driving circuitry based on the digital signals. First input circuitry provides a first adjustment signal to the adjustment circuitry. Second input circuitry provides a second adjustment signal to the adjustment circuitry in response to the control signal. The first adjustment signal is based on input of analog signals to a circuit element in the first input circuitry to control the first adjustment signal. The second input circuitry is responsive to the control signal to provide the second adjustment signal with the digital version of the input signals.
24 Citations
22 Claims
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1. Phase locked loop circuitry comprising:
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a voltage controlled oscillator, for adjusting phase or frequency characteristics of an output signal, having a first input terminal and an output terminal on which the output signal is provided; a phase and frequency detector which generates analog VCO input signals indicative of a phase difference or a frequency difference between the VCO output signal and a reference signal; conversion circuitry coupled to translate the analog VCO input signals from an analog form into digital versions to adjust the VCO output signal; signal driving circuitry, comprising a current source an output of which is a control signal generated by input of the digital version of the analog VCO input signals to the signal driving circuitry; first input circuitry providing a first adjustment signal to the first input terminal of the VCO; and second input circuitry providing a second adjustment signal to the first input terminal of the VCO in response to the control signal, wherein; the first adjustment signal is based on input of the VCO input signals in the analog form to a circuit element in the first input circuitry to control the first adjustment signal; and the control signal, to which the second input circuitry is responsive to provide the second adjustment signal, is determined with the digital versions of the VCO input signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 22)
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10. A method of adjusting an output signal of a device, comprising:
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generating analog input signals indicative of a phase difference or a frequency difference between the output signal and a reference signal; translating the analog input signals from an analog form into digital versions to adjust the output signal; generating a control signal from a current source by applying the digital versions of the analog input signals; providing a first adjustment signal to a first input terminal of the device; and providing a second adjustment signal to the first input terminal of the device in response to the control signal, wherein; the analog input signals are applied in the analog form to a circuit element in the first input circuitry to control the first adjustment signal; and the control signal, to which the second input circuitry is responsive to provide the second adjustment signal, is determined with the digital versions of the input signals. - View Dependent Claims (11, 12, 13, 14)
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15. A system including circuitry for varying a characteristic of a periodic signal comprising:
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adjustment circuitry responsive to an input signal, for adjusting a characteristic of the periodic signal, having a first input terminal and an output terminal on which the periodic signal is provided as an output signal; a phase detector which generates analog input signals indicative of a phase difference between the output signal and a reference signal; conversion circuitry coupled to translate the analog input signals from an analog form into digital versions to adjust the output signal; signal driving circuitry, comprising a current source the output of which is a control signal generated by input of the digital version of the analog input signals to the signal driving circuitry; first input circuitry providing a first adjustment signal to the first input terminal of the adjustment circuitry; and second input circuitry providing a second adjustment signal to the first input terminal of the adjustment circuitry in response to the control signal, wherein; the first adjustment signal is based on input of the adjustment circuitry input signals in the analog form to a circuit element in the first input circuitry to control the first adjustment signal; and the control signal, to which the second input circuitry is responsive to provide the second adjustment signal, is determined with the digital versions of the adjustment circuitry input signals. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification