Inductor and capacitor-based clock generator and timing/frequency reference
First Claim
1. An apparatus for providing a first reference signal, the apparatus comprising:
- a reference oscillator comprising an inductor and a capacitor, the reference oscillator to provide the first reference signal having a calibrated first frequency;
a voltage controller to provide a plurality of voltage control signals; and
a plurality of switchable, controlled reactance modules coupled to the reference oscillator and to the voltage controller, each reactance module of the plurality of reactance modules to provide a selected reactance in response to a corresponding voltage control signal of the plurality of voltage control signals to maintain the calibrated first frequency substantially constant.
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Accused Products
Abstract
In various embodiments, the invention provides a clock generator and/or a timing and frequency reference comprising an LC oscillator with a frequency controller to control and provide a stable resonant frequency. Such stability is provided over variations in a selected parameter such as temperature and fabrication process variations. The various apparatus embodiments include a sensor adapted to provide a signal in response to at least one parameter of a plurality of parameters; and a frequency controller adapted to modify the resonant frequency in response to the second signal. In exemplary embodiments, the sensor is implemented as a current source responsive to temperature fluctuations, and the frequency controller is implemented as a plurality of controlled reactance modules which are selectively couplable to the oscillator or to one or more control voltages. The controlled reactance modules may include fixed or variable capacitances or inductances, and may be binary weighted. Arrays of resistive modules are also provided, to generate one or more control voltages.
25 Citations
70 Claims
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1. An apparatus for providing a first reference signal, the apparatus comprising:
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a reference oscillator comprising an inductor and a capacitor, the reference oscillator to provide the first reference signal having a calibrated first frequency; a voltage controller to provide a plurality of voltage control signals; and a plurality of switchable, controlled reactance modules coupled to the reference oscillator and to the voltage controller, each reactance module of the plurality of reactance modules to provide a selected reactance in response to a corresponding voltage control signal of the plurality of voltage control signals to maintain the calibrated first frequency substantially constant. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An apparatus for providing a first reference signal the apparatus comprising:
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a harmonic oscillator comprising an inductor and a capacitor, the harmonic oscillator to provide the first reference signal having a first frequency and to operate without locking to an external reference signal; a plurality of resistive modules to generate a plurality of voltage control signals; a plurality of controlled reactance modules coupled to the harmonic oscillator and to the plurality of resistive modules, each reactance module of the plurality of reactance modules to provide a selected reactance in response to a corresponding voltage control signal of the plurality of voltage control signals to modify the first frequency; a coefficient register coupled to the plurality of switches, the coefficient register to store a plurality of switching coefficients; and a plurality of switches coupled to the plurality of resistive modules and to the plurality of controlled reactance modules, each switch of the plurality of switches responsive to a corresponding switching coefficient to couple a selected control voltage of the plurality of control voltages to a corresponding controlled reactance module. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. An integrated circuit for providing a plurality of output reference signals, the integrated circuit comprising:
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an oscillator comprising an inductor and a capacitor, the oscillator to provide a frequency reference signal having a resonant frequency; a sensor to provide a second signal in response to at least one parameter of a plurality of parameters; a voltage controller to provide a plurality of voltage control signals; a plurality of switchable, controlled reactance modules coupled to the oscillator and to the voltage controller, each reactance module of the plurality of reactance modules to provide a selected reactance in response to a corresponding voltage control signal of the plurality of voltage control signals to modify the resonant frequency; a frequency divider coupled to the oscillator and to provide the frequency reference signal having a first frequency; and a plurality of phase-locked loops coupled to the frequency divider, each phase-locked loop of the plurality of phase-locked loops having a corresponding divide ratio of a plurality of different divide ratios, each phase-locked loop of the plurality of phase-locked loops to phase lock to the frequency reference signal and provide an output signal having an output frequency determined from the first frequency and the corresponding divide ratio. - View Dependent Claims (31, 32, 33, 34, 35, 36)
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37. An integrated circuit for providing a first reference signal and having an integrated processor, the integrated circuit comprising:
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a harmonic oscillator comprising an inductor and a capacitor, the harmonic oscillator to provide the first reference signal having a first frequency; a plurality of resistive modules to generate a plurality of voltage control signals; a plurality of controlled capacitance modules coupled to the harmonic oscillator and to the plurality of resistive modules, each capacitance module of the plurality of capacitance modules to provide a selected capacitance in response to a corresponding voltage control signal of the plurality of voltage control signals to modify the first frequency; a coefficient register coupled to the plurality of switches, the coefficient register to store a plurality of switching coefficients; a plurality of switches coupled to the plurality of resistive modules and to the plurality of controlled capacitance modules, each switch of the plurality of switches responsive to a corresponding switching coefficient to couple a selected control voltage of the plurality of control voltages to a corresponding controlled capacitance module; a divider circuit coupled to the harmonic oscillator and to convert the first reference signal into a substantially square-wave clock signal having a substantially equal duty cycle; and a processor coupled to the divider circuit and to receive the clock signal.
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38. An apparatus for providing a first reference signal, the apparatus comprising:
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a reference oscillator comprising an inductor and a capacitor, the reference oscillator to provide the first reference signal having a calibrated first frequency; a voltage controller to provide at least one control voltage; and a first plurality of variable capacitors coupled to the reference oscillator and to the voltage controller, at least one variable capacitor of the first plurality of variable capacitors to provide a selected capacitance in response to the control voltage to maintain the calibrated first frequency substantially constant during a variation of a parameter in a first operating mode. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58)
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59. An integrated circuit for providing an output reference signal, the integrated circuit comprising:
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a reference oscillator comprising an inductor and a capacitor, the reference oscillator to provide a frequency reference signal having a resonant frequency; a voltage controller to provide a control voltage; a plurality of variable capacitors coupled to the reference oscillator and to the voltage controller, at least one variable capacitor of the plurality of variable capacitors to provide a selected reactance in response to the control voltage to maintain the resonant frequency substantially constant during a variation of at least one parameter in a first operating mode; and a frequency divider coupled to the reference oscillator and to provide the output reference signal having an output frequency determined from the resonant frequency and a divide ratio. - View Dependent Claims (60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70)
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Specification