Frequency controller for a monolithic clock generator and timing/frequency reference
First Claim
1. An apparatus for frequency control of an integrated, free-running harmonic oscillator, the apparatus comprising:
- a plurality of resistive modules adapted to generate a plurality of control voltages;
a plurality of controlled reactance modules coupled to the harmonic oscillator; and
a plurality of switches coupled to the plurality of resistive modules and to the plurality of controlled reactance modules, the plurality of switches responsive to a control signal to couple a first control voltage of the plurality of control voltages to a first controlled reactance module of the plurality of controlled reactance modules to modify a resonant frequency of the harmonic oscillator.
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Abstract
In various embodiments, the invention provides a frequency controller to control and provide a stable resonant frequency of a clock generator and/or a timing and frequency reference. 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 resonator 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.
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Citations
71 Claims
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1. An apparatus for frequency control of an integrated, free-running harmonic oscillator, the apparatus comprising:
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a plurality of resistive modules adapted to generate a plurality of control voltages; a plurality of controlled reactance modules coupled to the harmonic oscillator; and a plurality of switches coupled to the plurality of resistive modules and to the plurality of controlled reactance modules, the plurality of switches responsive to a control signal to couple a first control voltage of the plurality of control voltages to a first controlled reactance module of the plurality of controlled reactance modules to modify a resonant frequency of the harmonic oscillator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. An apparatus for frequency control of an integrated, free-running harmonic oscillator, the apparatus comprising:
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a resonator adapted to provide a first signal having a resonant frequency; a sensor adapted to provide a second signal in response to at least one parameter of a plurality of parameters; and a frequency controller coupled to the sensor and to the resonator, the frequency controller comprising a plurality of controlled capacitance modules comprising a plurality of fixed capacitances, variable capacitances, and a plurality of switches coupled to the plurality of the fixed capacitances and variable capacitances, the frequency controller adapted to modify an impedance element coupled to the resonator in response to the second signal to maintain the resonant frequency substantially constant in response to the at least one parameter. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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49. An apparatus for frequency control of a resonator, the resonator adapted to provide a first signal having a resonant frequency, the apparatus comprising:
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a coefficient register adapted to store a first plurality of coefficients; and a first array having a plurality of switchable reactance modules coupled to the coefficient register and to the resonator, each switchable reactance module responsive to a corresponding coefficient of the first plurality of coefficients to switch a corresponding reactance to the resonator to modify the resonant frequency. - View Dependent Claims (50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65)
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66. An apparatus for frequency control in response to temperature variation, the apparatus comprising:
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a resonator, the resonator adapted to provide a first signal having a resonant frequency; a negative transconductance amplifier coupled to the resonator; and a temperature compensator coupled to the resonator, the temperature compensator adapted to modify a current through the negative transconductance amplifier in response to temperature variation to maintain the resonant frequency substantially constant, the temperature compensator comprising a current source having at least one complementary to absolute temperature (CTAT) configuration, proportional to absolute temperature (PTAT) configuration, or proportional to absolute temperature squared (PTAT2) configuration. - View Dependent Claims (67, 68, 69)
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70. A frequency controller for frequency control of a resonator, the frequency controller comprising:
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a coefficient register adapted to store a first plurality of coefficients and a second plurality of coefficients; a current source adapted to provide a current corresponding to a temperature; a first array having a plurality of switchable resistive modules coupled to the coefficient register and further having a capacitive module, the first array further coupled through a current mirror to the current source to create at least one control voltage across at least one switchable resistive module of the plurality of switchable resistive modules, each switchable resistive module responsive to a corresponding coefficient of the second plurality of coefficients to switch the switchable resistive module to provide the control voltage to a control voltage node; and a second array having a plurality of switchable capacitive modules coupled to the coefficient register and to the resonator, each switchable capacitive module having a fixed capacitance and a variable capacitance, each switchable capacitive module responsive to a corresponding coefficient of the first plurality of coefficients to switch between the fixed capacitance and the variable capacitance and to switch each variable capacitance to the control voltage node.
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71. A frequency controller for frequency control of a resonator, the frequency controller comprising:
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a coefficient register adapted to store a first plurality of coefficients; a current source; a first array having a plurality of switchable resistive modules coupled to the coefficient register and coupled through a current mirror to the current source to create a plurality of control voltages; and a second array having a plurality of switchable and variable capacitive modules coupled to the coefficient register and to the resonator, the second array further selectively couplable to the first array, each switchable capacitive module responsive to a corresponding coefficient of the first plurality of coefficients to switch the variable capacitance to a selected control voltage of the plurality of control voltages.
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Specification