Abstract: A crystal oscillator emulator integrated circuit comprises a first temperature sensor that senses a first temperature of the integrated circuit. Memory stores calibration parameters and selects at least one of the calibration parameters based on the first temperature. A semiconductor oscillator generates an output signal having a frequency, which is based on the calibration parameters, and an amplitude. An amplitude adjustment module compares the amplitude to a predetermined amplitude and generates a control signal that adjusts the amplitude based on the comparison.

Abstract: A voltage controlled oscillator (VCO) is provided that includes an output buffer having a first buffer stage including a first transistor and a second buffer stage including a second transistor. The first and second transistors are connected in a cascaded emitter follower buffer arrangement.

Abstract: A PLL circuit which can absorb variation of phase noise characteristic due to temperature and individual difference and has a phase noise suppression characteristic stable in a wide frequency band is provided. The PLL circuit comprises, at the succeeding stage, a first register for storing a first parameter for controlling the loop gain, a first multiplier for multiplying the output of the phase comparator by a first parameter, a second register for storing a second parameter for controlling the response characteristic, a second multiplier for multiplying the output of the first multiplier by a second parameter, and a CPU for setting optimum parameters in the first and second registers depending on the use frequency band, the ambient temperature, and the device individual difference. By controlling the loop gain and the response characteristic to optimum values, a good suppression characteristic in a wide frequency band is achieved.

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.

Abstract: A method for compensating an oscillation frequency, a device, and a phase locked loop (PLL) is applied in the LC oscillating loop, including: sending voltage control signals to one end of a variable capacitor of an LC oscillating loop to generate oscillating signals in the LC oscillating loop through the voltage control signals; obtaining variable bias voltage that reflects changes of external parameters; and sending the variable bias voltage to the other end of the variable capacitor to compensate changes to the oscillation frequency of oscillation signals generated in the LC oscillating loop. This invention compensates the changes to the oscillation frequency of the circuit that contains the LC oscillating loop and improves the stability of the circuit oscillation frequency by sending bias voltage to one end of the variable capacitor of the LC oscillating loop.

Abstract: A temperature compensating circuit including a reference circuit, a transistor and a first circuit is provided. The reference circuit has a reference current and a resistance circuit, wherein the resistance circuit includes a first terminal receiving the reference current, a second terminal and a negative-temperature-coefficient resistor. The transistor has a drain, a source and a path disposed between the drain and the source, wherein the path of the transistor is connected in series with the resistance circuit, a gate of the transistor is electrically connected to the drain of the transistor and the second terminal of the resistance circuit, and the drain of the transistor produces a bias-voltage signal.

Abstract: An integrated circuit comprises a microelectromechanical (MEMS) resonator circuit that generates a reference frequency and that includes a semiconductor oscillator that generates resonator drive signal having a drive frequency and a MEMS resonator that receives the resonator drive signal. A temperature sensor senses a temperature of the integrated circuit. Memory stores calibration parameters and selects at least one of the calibration parameters as a function of the sensed temperature, wherein the drive frequency is based on the calibration parameters.

Abstract: An oscillation circuit includes an internal voltage generator and an oscillator. The internal voltage generator receives an external voltage and generates an internal voltage based on the external voltage. The internal voltage varies in linearly with an operational temperature. The oscillator generates a variable oscillation signal based on the internal voltage. A period of the variable oscillation signal varies in linearly with the operational temperature.

Abstract: A low temperature coefficient oscillator including a current generator, a first and a second voltage generator, an amplifier, a resistor, a switch, a capacitor and an oscillating unit is provided. The current generator generates a first through a fourth current according to a control signal. The first voltage generator generates a first voltage according to the first current. The second voltage generator generates a second voltage according to the second current and a frequency signal. The amplifier generates the control signal according the first and second voltages. The resistor is coupled between a first terminal of the switch and ground, and a first terminal thereof receives the third current. The switch is conducted or not according the frequency signal. The capacitor is coupled between a second terminal of the switch and ground. The oscillating unit generates the frequency signal according to the fourth current and a voltage of the capacitor.

Abstract: Systems and methods are disclosed herein for using a switched mode TCXO or VC-TCXO in a coherent receiver application where the switched mode TCXO or VC-TCXO may operate either in an active compensation mode to compensate for temperature induced frequency error or in a second fixed compensation mode where the TCXO or VC-TCXO is not compensated for temperature. The switched mode TCXO or VC-TCXO is operated in the active compensation mode when receiver performance may be improved from a reduction in the range of oscillator frequency error. The switched mode TCXO or VC-TCXO may be switched to operate in the fixed compensation mode when receiver performance is sensitive to discontinuities in the phase, frequency, and/or frequency rate of the oscillator clock when temperature compensation is applied. In addition, the switched mode VC-TCXO may operate in a transparent mode to allow change to the oscillator or a latched mode to prevent change to the oscillator.

Abstract: A temperature-compensated crystal oscillator including an oscillation circuit which includes an oscillator, a temperature detector, a voltage variable capacitance element coupled to an oscillation loop of the oscillation circuit, and a temperature compensation circuit. The temperature compensation circuit is configured to apply a compensation voltage to the voltage variable capacitance element to compensate a temperature change in response to temperature data detected by the temperature detector. The temperature compensation circuit has a plurality of correction point data. The respective correction point data is set in advance for each divided temperature zone, selects a first correction point data in a lower temperature zone and a second correction point data in a higher temperature zone, as compared with the detected temperature data, performs an interpolation between the first and second correction point data by a weighted averaged first-order interpolation, and generates the compensation voltage.

Abstract: A lead wire led-out type crystal oscillator of constant temperature type for high stability is disclosed, which includes a heat supply body that supplies heat to a crystal resonator from which a plurality of lead wires are led out, to maintain the temperature constant. The heat supply body includes a heat conducting plate which has through-holes for the lead wires and is mounted on the circuit board, and which faces, and is directly thermally joined to, the crystal resonator and a chip resistor for heating which is mounted on the circuit board adjacent to the heat conducting plate, and is thermally joined to the heat conducting plate.

Abstract: Device and method for temperature compensation in a clock oscillator using quartz crystals, which integrates dual crystal oscillators. The minimal power consumption is achieved through an efficient use of a processor in charge of the synchronization of the two oscillators. The invention is particularly adapted for the provision of a precise reference clock in portable radiolocalization devices.

Abstract: An integrated circuit comprises an oscillator that generates an oscillator signal. A first counter generates a first count based on transitions of the oscillator signal. A first circuit generates a match signal based on the first count and a reference count. A second counter generates a second count that is initialized at a starting count and adjusts the second count based on transitions of a reference clock signal. An output circuit outputs an oscillator speed based on the second count and the match signal. The oscillator speed is defined by a range that is independent of a frequency of the reference clock signal.

Abstract: A crystal oscillator includes a crystal unit and a voltage-variable capacitive element that is connected to the crystal unit in series, the crystal oscillator varying an oscillation frequency by applying a control voltage between terminals of the voltage-variable capacitive element and by varying a series equivalence capacitance at a side of the oscillator circuit when observed between terminals of the crystal unit. The crystal oscillator further includes a first resistor and a second resistor for dividing the control voltage. At least one of the first resistor and the second resistor is a temperature sensing resistor, the resistance of which changes depending on a temperature, so as to correct frequency temperature characteristics of the oscillation frequency.

Abstract: The invention discloses a varactor device (100) for improved temperature stability, comprising a first varactor (160) connected to a decoupling network (150). The device further comprises a voltage stabilizer (110), said stabilizer comprising a capacitor (140) and a temperature dependent capacitor (130), and in that the stabilizer comprises means for connection to a DC-feed (120). Suitably, the decoupling network (150) is connected in parallel to the first varactor (160), and the capacitor (140) of the voltage stabilizer (110) is connected in parallel to the decoupling network (150), the temperature dependent capacitor (130) of the voltage stabilizer (110) being connected in series to the diode of the voltage stabilizer (110).

Abstract: Provided is an oscillator including: a MEMS resonator for mechanically vibrating; an output oscillator circuit for oscillating at a resonance frequency of the MEMS resonator to output an oscillation signal; and a MEMS capacitor for changing a capacitance thereof caused by a change in a distance between an anode electrode and a cathode beam according to an environmental temperature.

Abstract: A programmable reference-less oscillator provides a wide range of programmable output frequencies. The programmable reference-less oscillator is implemented on an integrated circuit that includes a free running controllable oscillator circuit such as a voltage controlled oscillator (VCO), a programmable divider circuit coupled to divide an output of the controllable oscillator circuit according to a programmable divide value. A non-volatile storage stores the programmed divide value and a control word that controls the output of the controllable oscillator circuit. The control word provides a calibration capability to achieve a desired output frequency in conjunction with the programmable divider circuit. Open loop temperature compensation is achieved by adjusting the control word according to a temperature detected by a temperature sensor on the integrated circuit. Additional clock accuracy may be achieved by adjusting the control word for process as well as temperature.

Abstract: An oven controlled crystal oscillator capable of uniformly transmitting heat from the heat generator to improve the frequency-temperature characteristics. The oven controlled crystal oscillator includes a high thermal conductivity plate having high thermal conductivity and provided on one side of a substrate, where the crystal resonator is provided, in such a manner to contact the resistors, the transistor, the crystal resonator, and the temperature sensor. This structure can transmit heat from the resistors and the transistor as the heat generator to the crystal resonator and the temperature sensor rapidly with less heat loss to assure a uniform temperature inside the substrate, thereby improving the frequency-temperature characteristics.

Abstract: An oscillator includes an oscillator circuit and a resonator that produces an output frequency. A temperature compensation circuit is coupled to the oscillator circuit. The temperature compensation circuit stabilizes the output frequency in response to changes in temperature. At least one temperature sensor and a temperature sensor signal modification circuit are coupled to the temperature compensation circuit. The temperature sensor signal modification circuit receives a temperature signal from the temperature sensor and generates a modified temperature sensor signal that is transmitted to the temperature compensation circuit.

Abstract: A crystal oscillator in which a temperature characteristic of an oscillation frequency is improved to omit a measurement operation of the temperature characteristic of the oscillator, and manufacturing is facilitated to reduce a manufacturing time. In the crystal oscillator, a power voltage is applied to a collector of a transistor via series connection of an inductor for resonance and a resistance, a crystal unit is disposed in a loop which returns to an emitter of the transistor from a point between the inductor L4 and the resistance, and further, in the loop, a first parallel circuit in which a stationary capacitor having a negative temperature coefficient and a stationary capacitor having a zero temperature coefficient are connected in parallel with each other is inserted between an oscillation output taking point and the collector.

Abstract: A temperature correcting apparatus divides an actually measured waveform of correcting voltages, which are required at each of different temperatures, by a minimum resolution of D/A conversion; obtains voltage digital values representing voltage values at individual dividing points of the actually measured waveform, and obtains times corresponding to the voltage digital values; prestores pairs of the voltage digital values and times together with addresses as correcting data; reads out the correcting data in response to the detection address representing the temperature; extracts or calculates from the correcting data the voltage digital values and times about the correcting voltages required by the detection address; and sequentially supplying a D/A converter (36) with the resultant voltage digital values in synchronization with the corresponding times.

Abstract: A first order function generation circuit receives a signal from a temperature sensor circuit, and generates a first order function control signal V1 that is affected by the ambient temperature. A fourth order and fifth order approximation function generation circuit receives signals from the temperature sensor circuit and from the third order approximation function generation circuit, and generates a fourth and fifth order approximation function control signal V45 that is affected by the ambient temperature. A peak change point adjustment circuit outputs a signal to adjust the value of a peak change point temperature Ti for the third order approximation function generation circuit, the first order generation function circuit and the fourth order and fifth order approximation function generation circuit. A temperature compensation circuit adds together control signals V0, V1, V3 and V5, and outputs the resultant signal Vc.

Abstract: Disclosed are various embodiments of temperature-compensated relaxation oscillator circuits that may be fabricated using conventional CMOS manufacturing techniques. The relaxation oscillator circuits described herein exhibit superior low temperature coefficient performance characteristics, and do not require the use of expensive off-chip high precision resistors to effect temperature compensation. Positive and negative temperature coefficient resistors arranged in a resistor array offset one another to provide temperature compensation in the relaxation oscillator circuit.

Abstract: The invention relates to a proximity switch, particularly an inductive proximity switch, with an oscillator having an at least partly self-compensated feedback network influenceable by a target to be detected, as well as an oscillator amplifier.

Abstract: A package device, such as an oscillator, includes a package module, a circuit module, a plurality of conductive pins, and a plurality of conductive arms. The package module defines an airtight space therein. The circuit module is disposed in the airtight space in the package module. Each of the conductive pins extends into the airtight space in the package module. Each of the conductive arms is disposed in the airtight space, and has a first end that is connected to the circuit module, a second end that is connected to a respective one of the conductive pins, and an intermediate portion that extends between the first and second ends thereof and that has a length longer than the shortest distance between the first and second ends thereof.

Abstract: A voltage-controlled oscillator has an oscillation frequency controlled through a voltage applied across ends of a variable-capacitance element. The voltage-controlled oscillator has a frequency control bias circuit which applies to a first end of the variable-capacitance element a voltage for frequency control according to a control voltage, a first current source which generates a first current according to the control voltage, a second current source which generates a second current according to temperature, independent of the control voltage, a converting resistor which converts a current, obtained by adding together the first and second currents, into a voltage, and a temperature compensation bias circuit which applies to the second end of the variable-capacitance element a voltage for temperature compensation according to the voltage produced by the converting resistor.

Abstract: The present invention provides a constant gm circuit that generates a bias current for a emitter/source-coupled multivibrator oscillator. The stable gm bias limits the temperature dependence of the oscillator. Trimming a resistor in the constant gm circuit compensates for process variations, and current sources may be provided that are mirrors of the bias current that are also substantially independent of the supply voltage. The present invention provides an oscillator with less that 1% frequency changes due to PVT variations.

Abstract: An oscillator is provided that includes an oscillating structure generating an output signal with a frequency that drifts as a function of a parameter of its environment, and a compensation circuit coupled to the oscillating structure. The oscillating structure has a ring structure that includes delay cells looped together, and the compensation circuit supplies a compensation signal to the oscillating structure. The compensation signal varies as a function of changes in the parameter in order to compensate for the drift in the frequency of the generated signal. This makes it possible to compensate for oscillator temperature drifts in the absence of a regulation loop.

Abstract: The present invention provides a constant temperature oven type crystal oscillator for reducing the difference of frequency stability caused by controlling the temperature in the oscillator when detecting the change of the outside-air temperature and controlling the amount of generated heat of a heat source provided in the oscillator.

Abstract: An oscillation circuit of the present invention includes: an oscillation section for which an output frequency is controlled based on a control signal depending on an ambient temperature; a temperature compensation circuit for supplying the control signal to this oscillation section; and a switching switch circuit consisting of an output buffer and a temperature sensor output switch for which ON and OFF are controlled so that any one of an oscillation output from the oscillation section and a temperature sensor output from the temperature compensation circuit is outputted. The temperature sensor output switch is structured so that transfer gate switches are connected in a two-stage serial manner and a third switch connected to a fixed potential is sandwiched between these connection points. When an oscillation output is outputted, the transfer gate switches are OFF and the third switch is ON and, when a temperature sensor output is outputted, the transfer gate switches are ON and the third switch is OFF.

Abstract: A system is provided for the regulation of temperature of a crystal oscillator, that system having a thermally conductive support disposed upon a substrate and upon which is disposed the crystal oscillator, an array of thermal vias disposed around the crystal oscillator within the substrate, at least one primary heater communicating with the support, a thermal enclosure communicating with the array of thermal vias, and a at least one secondary heater communicating with the enclosure.

Abstract: A voltage-controlled oscillator is provided that avoids use of any crystal resonator, or any resonator that is external to and not integrated upon the voltage-controlled oscillator monolithic substrate. The present oscillator can receive two or more parameters that would likely have an affect on the oscillator frequency, yet the oscillator includes compensating transfer functions that will remove, or correct for, that effect. Transfer functions involve electronic subsystems implemented in hardware or software that receive the input parameter that has changed from a nominal value, and will note the drift in output frequency, yet will compensate for that drift so that the output frequency remains near the nominal value. The voltage-controlled oscillator preferably is an LCVCO, and the transfer function outputs can be summed to take into account multiple parameter changes.

Abstract: A method of manufacturing a temperature compensated oscillator including the steps of assembling an oscillator in which an IC chip constituting a temperature compensation circuit with an oscillation circuit and a compensation data storage circuit, and a resonator for the oscillation circuit are mounted in a package; adjusting the resonator with an oscillation frequency of the oscillation circuit to a desired oscillation frequency in condition that the oscillator is kept at a reference temperature, in condition that a temperature compensation function of the temperature compensation circuit is disabled; sealing the resonator hermetically; creating temperature compensation data and storing it into the compensation data storage circuit; and enabling the temperature compensation function of the temperature compensation circuit.

Abstract: One embodiment of a method of generating a clock signal and synchronizing the generated clock signal with a digital data stream comprises generating a clock signal using an oscillator, identifying a transition in a portion of the data stream, and synchronizing a transition of the clock signal with the identified transition in the data stream by changing a state of the oscillator using control circuitry in response to the identification of the transition in the data stream, wherein the clock signal is synchronized with the data stream for both situations where the oscillator operates at a frequency greater than the data rate and where the oscillator operates a frequency less than the data rate. Other methods and systems are also provided.

Abstract: There is provided a temperature detecting apparatus for improving operational characteristics, which vary according to the temperature, of elements in a semiconductor memory device. The temperature detecting apparatus of the present invention includes: a first oscillator that outputs a first oscillating signal in response to a first oscillator reset signal, the first oscillating signal being independent of the temperature; a second oscillator that outputs a second oscillating signal in response to a second oscillator enable signal, the second oscillating signal being dependent on the temperature; a comparator that compares an output pulse of the first oscillator with an output pulse of the second oscillator and then outputs a temperature detection comparison signal; and an output unit that outputs a temperature detection signal in response to an input of the temperature detection comparison signals.

Abstract: A temperature-dependent oscillator includes a first current source, wherein a first current provided by the first current source has a positive temperature coefficient, a second current source serially connected to the first current source, wherein a second current provided by the second current source has a negative temperature coefficient, and a capacitor serially connected to the first current source and parallel connected to the second current source.

Abstract: A system and method for providing temperature compensation in a oscillator component (such as a crystal oscillator component) that includes a closely-located temperature sensing device. The crystal oscillator component in example systems and methods is exposed to a temperature profile during a calibration procedure. Temperature and frequency data are collected and applied to coefficient generating function according to a temperature compensation model to generate a set of coefficients that are used in the temperature compensation model in an application device. The generated coefficients are stored in a coefficient memory accessible to an application device during operation.

Abstract: A microcomputer includes an oscillator for generating a clock signal having a frequency by using a CR circuit, a multiplier for outputting the clock signal having a multiplied frequency relative to the frequency generated by the oscillator based on data from an external source, a temperature detection unit for detecting temperature at a proximity of the CR circuit, a storage unit for storing data that enables the multiplied frequency of the clock signal in an output from the multiplier to have a constant value based on a temperature-dependent oscillation characteristic of the oscillator, and a control unit for setting a multiplication value for generating the multiplied frequency of the clock signal to the multiplier based on the data in the storage unit that is correlated to the temperature detected by the temperature detection unit.

Abstract: A method for generating a temperature-compensated timing signal that includes counting, within an update interval, a first number of oscillations of a first micro-electromechanical (MEMS) resonator, a second number of oscillations of a second MEMS resonator and a third number of oscillations of a digitally controlled oscillator (DCO), computing a target DCO count based on the first number and second number of oscillations, computing a loop error signal based on the target DCO count and the third number of oscillations, and modifying an output frequency of a temperature-dependent (DCO) timing signal based on the loop error signal. The duration of the update interval may also be modified based on temperature conditions, and the update interval may also be interrupted and the output frequency immediately adjusted, if a significant temperature change is detected. Thus, dynamic and precise temperature compensation is achieved that accommodates constant, slowly changing, and rapidly changing temperature conditions.

Abstract: There are many inventions described and illustrated herein. In one aspect, the present invention is directed to a compensated microelectromechanical oscillator, having a microelectromechanical resonator that generates an output signal and frequency adjustment circuitry, coupled to the microelectromechanical resonator to receive the output signal of the microelectromechanical resonator and, in response to a set of values, to generate an output signal having second frequency. In one embodiment, the values may be determined using the frequency of the output signal of the microelectromechanical resonator, which depends on the operating temperature of the microelectromechanical resonator and/or manufacturing variations of the microelectromechanical resonator. In one embodiment, the frequency adjustment circuitry may include frequency multiplier circuitry, for example, PLLs, DLLs, digital/frequency synthesizers and/or FLLs, as well as any combinations and permutations thereof.

Abstract: There is provided a technique which is capable of detecting a temperature of a semiconductor device with high precision. A temperature detection circuit detecting a temperature of a semiconductor device includes a first short-cycle oscillator generating a first clock signal having positive temperature characteristics with respect to a frequency, a second short-cycle oscillator generating a second clock signal having negative temperature characteristics with respect to the frequency, and a temperature signal generation unit generating a temperature signal which is varied according to the temperature of the semiconductor device based on the first and second clock signals.

Abstract: There is disclosed a self-calibrating resistor-capacitor (RC) oscillator in which a resistor has a resistance value varied minimally by temperature change and process variation, a capacitor has a capacitance value selected adequately according to needs, and the resistor and capacitor are configurable as a one-chip by a complementary metal-oxide semiconductor (CMOS) process. The self-calibrating RC oscillator comprises a resistor part including a first resistor having a resistance value reduced with increase in temperature and a second resistor connected in series with the first resistor and having a resistance value increasing with increase in temperature.

Abstract: A mechanism for utilizing a single set of one or more thermal sensors, e.g., thermal diodes, provided on the integrated circuit device, chip, etc., to control the operation of the integrated circuit device, associated cooling system, and high-frequency PLLs is provided. By utilizing a single set of thermal sensors to provide multiple functions, e.g., controlling the operation of the integrated circuit device, the cooling system, and the PLLs, silicon real-estate usage is reduced through combining circuitry functionality. Moreover, the integrated circuit device yield is improved by reducing circuitry complexity and increasing PLL robustness to temperature. Furthermore, the PLL circuitry operating range is improved by compensating for temperature.

Abstract: A method for controlling/regulating a physical variable of a dynamic system to a specific desired value profile with use made of a pulse modulator that generates a sequence of discrete modulation signals that affect the control or regulation of the physical variable. The method involves repeated execution of: determining an exact value or an approximation for the deviation between the momentary desired value and the momentary actual value of the physical variable; determining the respective change in the deviation which would result from the maintenance of the momentary modulation signal or the switching over to the other modulation signals; and generating that modulation signal which results in the best approximation of the momentary desired value.

Abstract: The invention discloses a varactor device (100) for improved temperature stability, comprising a first varactor (160) connected to a decoupling network (150). The device further comprises a voltage stabilizer (110), said stabilizer comprising a capacitor (140) and a temperature dependent capacitor (130), and in that the stabilizer comprises means for connection to a DC-feed (120). Suitably, the decoupling network (150) is connected in parallel to the first varactor (160), and the capacitor (140) of the voltage stabilizer (110) is connected in parallel to the decoupling network (150), the temperature dependent capacitor (130) of the voltage stabilizer (110) being connected in series to the diode of the voltage stabilizer (110).

Abstract: A design structure for an apparatus for utilizing a single set of one or more thermal sensors, e.g., thermal diodes, provided on the integrated circuit device, chip, etc., to control the operation of the integrated circuit device, associated cooling system, and high-frequency PLLs, is provided. By utilizing a single set of thermal sensors to provide multiple functions, e.g., controlling the operation of the integrated circuit device, the cooling system, and the PLLs, silicon real-estate usage is reduced through combining circuitry functionality. Moreover, the integrated circuit device yield is improved by reducing circuitry complexity and increasing PLL robustness to temperature. Furthermore, the PLL circuitry operating range is improved by compensating for temperature.

Abstract: A system and method for providing temperature compensation in a oscillator component (such as a crystal oscillator component) that includes a closely-located temperature sensing device. The crystal oscillator component in example systems and methods is exposed to a temperature profile during a calibration procedure. Temperature and frequency data are collected and applied to coefficient generating function according to a temperature compensation model to generate a set of coefficients that are used in the temperature compensation model in an application device. The generated coefficients are stored in a coefficient memory accessible to an application device during operation.

Abstract: A reference clock circuit (170), has a low-power mode, in which the frequency consumption is reduced, and including an internal counter, accumulating time spent in low-power mode. The circuit includes a crystal resonator (60), an oscillator circuit (70), and a temperature compensation circuit (80), providing a stable clock output (85). During low-power mode temperature compensation can be switched off. The circuit further provides a wakeup signal (107) after a preset time in low-power mode.

Abstract: The invention provides a method and apparatus to optimally estimate and adaptively compensate the temperature-induced frequency drift of a crystal oscillator in a navigational signal receiver. A Read-Write memory encodes two tables, one for looking up frequency drift values versus temperature readings and another one for valid data confirmation on the first table. The initially empty look-up table is gradually populated with frequency drift values while the receiver computes the frequency drift along with its position. During initial start of the receiver or re-acquisition of satellite signals, the stored frequency drift value corresponding to the current temperature is used. If no valid frequency drift value is available, the frequency drift value is computed based on the existing frequency drift values in the table. This invention reduces the Time-To-First-Fix (TTFF) of the receiver and enables the receiver to self-calibrate, thus no additional factory calibration would be necessary.