Abstract: Clock synchronization error is corrected or minimized by fitting a parabolic f(T) function to the crystal's data, and compensating for sampling period drift in an Analog to Digital Converter (ADC) at various temperatures.

Abstract: An oscillation circuit including a reference voltage generation circuit that adds a proportional-to-absolute-temperature (PTAT) output, which increases in proportion to an absolute temperature, to a complementary-to-absolute-temperature (CTAT) output, which decreases in proportion to an absolute temperature, to generate and output a reference voltage. The oscillation circuit generates an oscillation signal having a desired and fixed frequency.

Abstract: A quartz transducer having four or more crystal-controlled oscillators intended for measurement of applied pressure and temperature. All four oscillators are controlled by crystal quartz resonators operating in the thickness-shear mode. Two crystals measure the pressure and temperature respectively. A third crystal is a reference, and the fourth crystal may be another reference crystal or a second temperature crystal. The output of the latter is either phase leading or phase lagging the thermal response of the main temperature sensor.

Abstract: A temperature-compensated crystal oscillator includes a crystal resonator; and an oscillator circuit for performing temperature compensation.

Abstract: A signal generator for a transmitter or a receiver for transmitting or receiving RF-signals according to a given communication protocol includes an oscillator and a mismatch compensator. The oscillator is configured to provide a signal generator output signal having a signal generator output frequency and comprises a fine tuning circuit for providing a fine adjustment of the signal generator output frequency based on a fine tuning signal and a coarse tuning circuit for providing a course adjustment of the signal generator output frequency based on a coarse tuning signal.

Abstract: A semiconductor device includes: a resistance R whose resistance value varies in response to a substrate temperature variation; a resistance corrector that is coupled in series with the resistance R and switches its resistance value by a preset resistance step width to suppress a resistance value variation of the resistance R; a first voltage generator for generating a first voltage that varies in response to the substrate temperature; a second voltage generator for generating second voltages Vf1 to Vfn?1 for specifying the first voltage at a point when a switching operation of the resistance value of the resistance corrector is performed; and a resistance switch unit for switching the resistance value of the resistance corrector by comparing the first voltage and the second voltages Vf1 to Vfn?1.

Abstract: A fractional-N divider supplies a divided clock signal. An adjusted divided clock signal is generated in a digital-to-time converter circuit having a delay linearly proportional to digital quantization errors of the fractional-N divider. The adjusted divided clock signal is generated based on first and second capacitors charging to a predetermined level. The charging of the first and second capacitors is interleaved in alternate periods of the divided clock. The charging of each capacitor with a current corresponding to respective digital quantization errors is interleaved with charging with a fixed current. A first edge of a first pulse of the adjusted divided clock signal is generated in response to the first capacitor charging to a predetermined voltage and a first edge of a next pulse of the adjusted divided clock signal is generated in response to the second capacitor charging to the predetermined voltage.

Abstract: A substantially temperature-independent LC-based oscillator is achieved using an LC tank that generates a tank oscillation at a phase substantially equal to a temperature null phase. The temperature null phase is a phase of the LC tank at which variations in frequency of an output oscillation of the LC-based oscillator with temperature changes are minimized. The LC-based oscillator further includes frequency stabilizer circuitry coupled to the LC tank to cause the LC tank to oscillate at the phase substantially equal to the temperature null phase.

Abstract: A system and method is disclosed that provides a technique for generating an accurate time base for MEMS sensors and actuators which has a vibrating MEMS structure. The accurate clock is generated from the MEMS oscillations and converted to the usable range by means of a frequency translation circuit.

Abstract: One embodiment relates to a method of compensating for crystal frequency variation over temperature. An example method includes obtaining an indication of temperature, computing a temperature compensation value based on the indication of temperature and a piecewise linear temperature compensation approximation, and compensating for a temperature offset in a crystal reference signal by adjusting a division ratio of a fractional divider in a phase-locked loop. The piecewise linear temperature compensation approximation can represent an approximation of frequency error in a crystal reference signal originating from a crystal over temperature. The piecewise linear temperature compensation approximation can be, for example, a linear approximation, a quadratic approximation, or a cubic approximation.

Abstract: The present invention relates to an oscillating device, which comprises a driving module and an oscillating module. The driving module is used for producing a first driving voltage and a second driving voltage. The oscillating module comprises a first symmetric load circuit, a second symmetric load circuit, and a bias circuit. The first symmetric load circuit and the second symmetric load circuit produce a bias according to the first driving voltage. The bias circuit produces a bias current according to the second driving voltage. The oscillating module produces an oscillating signal according to the first driving voltage and the bias current, where the bias current is proportional to the bias. Thereby, by making the driving signal produced by driving module proportional to the bias of the oscillating module, simple compensation for temperature and process can be performed. Thereby, the frequency can be tuned using a few calibration bits.

Abstract: A method for manufacturing a quartz crystal unit, comprising the steps of forming a quartz crystal tuning fork shape having a quartz crystal tuning fork base, and first and second quartz crystal tuning fork tines, a quartz crystal tuning fork resonator having the quartz crystal tuning fork shape, forming at least one groove in at least one of opposite main surfaces of each of the first and second quartz crystal tuning fork tines, determining each of a length of the at least one groove and an overall length of the quartz crystal tuning fork resonator so that a series resistance R1 of a fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a series resistance R2 of a second overtone mode of vibration thereof, housing the quartz crystal tuning fork resonator in a case, connecting a lid to the case, and disposing a metal or a glass in a through-hole of the case.

Abstract: An LC oscillator tank that generates a tank oscillation at a phase substantially equal to a temperature null phase. The oscillator further includes frequency stabilizer circuitry coupled to the LC oscillator tank to cause the LC oscillator tank to operate at the temperature null phase. In one aspect of the disclosure, a feedback loop may split the output voltage of the LC tank into two voltages having different phases, where each voltage is independently transformed into a current through programmable transconductors, The two currents may be combined to form a resultant current which is then applied to the LC tank. The phase of the resultant current is such that the LC tank operates at an impedance condition that achieves frequency stability across temperature.

Abstract: The LC tank of a VCO includes a main varactor circuit and temperature compensation varactor circuit coupled in parallel with the main varactor circuit. The main varactor is used for fine tuning. The temperature compensation varactor circuit has a capacitance-voltage characteristic that differs from a capacitance-voltage characteristic of the main varactor circuit such that the effects of common mode noise across the two varactor circuits are minimized. The LC tank also has a plurality of switchable capacitor circuits provided for coarse tuning. To prevent breakdown of the main thin oxide switch in each of the switchable capacitor circuits, each switchable capacitor circuit has a capacitive voltage divider circuit that reduces the voltage across the main thin oxide switch when the main switch is off.

Abstract: A temperature compensation circuit is disclosed. A temperature compensation circuit may include a temperature coefficient generator configured to generate a first signal and a second signal, wherein the first signal is proportional-to-absolute-temperature (ptat) and the second signal is negatively-proportional-to-absolute-temperature (ntat), a first programmable element configured to multiply at a first programmable ratio an amplitude of a third signal having a negative temperature coefficient from a first temperature to a second temperature, and a second programmable element configured to multiply at a second programmable ratio an amplitude of a fourth signal having a positive temperature coefficient from the second temperature to a third temperature.

Abstract: A temperature compensation apparatus may include a sense circuit configured to produce a sense voltage that is dependent on temperature and a temperature compensation circuit configured to receive the sense voltage and produce a temperature compensation control signal to control a compensation capacitor array of an oscillator. The temperature compensation circuit may be configured to calibrate the control signal to have a first value at a first temperature. The temperature compensation circuit may also be configured to calibrate a trimming level (e.g., slope) of the control signal.

Abstract: One embodiment of communication system comprises a crystal oscillator configured to output a reference clock; cellular radio frequency (RF) and baseband phase locked loops configured to receive the reference clock within a cellular module and compensate for calculated frequency errors between a received cellular downlink signal and a cellular local oscillator signal during operation of the cellular module; global positioning system (GPS) frequency compensation circuitry configured to receive the reference clock within a GPS module and compensate for calculated frequency errors during operation of the GPS module; and a temperature sensing circuit which includes a plurality of sensing resistors and is configured to output a signal corresponding to a temperature of a reference crystal which is translated to a frequency deviation, wherein the (GPS) frequency compensation circuitry is configured to offset the frequency deviation and output a temperate compensated signal to meet GPS clock frequency requirements.

Abstract: Circuits, apparatuses, and methods are disclosed for oscillators. In one such example oscillator circuit, a plurality of delay stages are coupled in series. A variable delay circuit stage is coupled to the plurality of delay stages and is configured to delay a signal through the variable delay circuit stage by a variable delay. The variable delay increases responsive to a rising magnitude of a supply voltage provided to the variable delay circuit stage.

Abstract: A communication apparatus having a first and second wireless communications modules is provided. The first wireless communications module includes a receiving unit receiving RF signals from an air interface, a signal processing module performing frequency down conversion on the RF signals to generate baseband signals according to a clock signal, and a processor processing the baseband signals. The processor further detects an ON/OFF status of the second wireless communications module to obtain a detection result and compensates for frequency drift of the clock signal according to the detection result.

Abstract: Methods for compensating the existing crystal oscillator frequencies in extended temperature ranges. Utilizing existing crystal oscillators on any system design which may have quartz crystals with associated circuitry to deliver frequency or timing reference signals and increasing the accuracy of such by additional circuitry.

Abstract: A constant voltage circuit which can realize a low consumption current, and a crystal oscillation circuit using the constant voltage circuit. The constant voltage circuit is provided with a temperature characteristic regulation element, in order to minimize a difference between a negative slope of a voltage response of a constant voltage to a temperature change and a negative slope of a voltage response of the smallest operation voltage that can oscillate in the crystal oscillation circuit to the temperature change, so that the consumption current of the crystal oscillation circuit is decreased. When the constant current generated by the constant voltage circuit is decreased, the consumption current of the constant voltage circuit is decreased, and the consumption current of the whole oscillation device is decreased.

Abstract: A piezoelectric device includes an insulating substrate, a piezoelectric vibration device that is mounted on a device mounting pad, a metal lid member that seals the piezoelectric vibration device in an airtight manner, an external pad that is arranged outside the insulating substrate, an oscillation circuit, a temperature compensation circuit, and a temperature sensor. The lid member and the temperature sensor or the lid member and the IC component are connected to each other so as to be heat-transferable, and a heat transfer member having thermal conductivity higher than that of the material of the insulating substrate is additionally included.

Abstract: A crystal unit and a thermistor with negative resistance-temperature characteristics are housed in a thermostatic oven heated by a heater. A transistor driving the heater is controlled by an output of a differential amplifier, the thermistor is placed between a power supply voltage and an inverting input of the amplifier, and a first resistor used to adjust the temperature of a zero temperature coefficient point of the crystal unit is installed between the inverting input and a ground point. A second resistor is installed between the power supply voltage and a non-inverting input of the amplifier and a third resistor is installed between the non-inverting input and ground point. One of the second and third resistors is a resistor assembly made up of a plurality of resistance elements and one of these resistance elements is provided with positive resistance-temperature characteristics and adapted to detect ambient temperature.

Abstract: A communication terminal includes a crystal oscillator, a transceiver and circuitry. The crystal oscillator belongs to a specified type in which a dependence of an output frequency on temperature has one or more temperature dependence coefficients. The transceiver is arranged to operate an AFC loop having an initial frequency accuracy requirement that is more stringent than an uncompensated frequency accuracy of the crystal oscillator. The circuitry is arranged to determine output frequencies of the crystal oscillator at respective operating temperatures, to compute the temperature dependence coefficients based on the output frequencies and operating temperatures, to correct a frequency error in the output frequency using the dependence and the temperature dependence coefficients, to ascertain that the corrected frequency error meets the initial frequency accuracy requirement, and to subsequently correct a frequency of the received signal using the AFC loop.

Abstract: A reference circuit, an oscillator architecture that includes the reference circuit and a method for operating the reference circuit are described. In one embodiment, the reference circuit includes a voltage reference generator configured to generate a reference voltage and a current reference generator configured to generate a reference current based on the reference voltage. The current reference generator includes a level shifter circuit configured to generate intermediate voltages based on the reference voltage, a first current reference circuit configured to generate intermediate currents based on the intermediate voltages, where the intermediate currents are correlated to the reference voltage, and a second current reference circuit configured to combine the intermediate currents to generate the reference current. Other embodiments are also described.

Abstract: To provide a reference frequency generating device that can output a highly accurate reference frequency signal even if a reference signal becomes unable to be acquired. The reference frequency generating device includes a synchronization circuit, a temperature sensor, and a controller. The synchronization circuit controls a reference frequency signal outputted from a voltage controlled oscillator, by a control signal obtained based on a reference signal. The temperature detector detects a temperature of the voltage controlled oscillator being used. When the reference signal is unable to be acquired, the controller corrects a voltage controlled signal in consideration of a distortion in the aging characteristic of the voltage controlled oscillator based on a rate of change with time in a slope of the oscillator temperature, and generates a holdover control signal based on corrected contents to control the voltage controlled oscillator.

Abstract: A calibration circuit includes at least two compensation circuits and a comparator. The at least two compensation circuits are coupled to an input signal for outputting at least a first compensation signal and a second compensation signal respectively. The comparator is coupled to the first compensation signal and the second compensation signal for outputting a calibration signal, where the calibration signal is used for determining an oscillation frequency of a crystal oscillator to achieve a purpose of frequency compensation with a temperature.

Abstract: A gas cell unit includes a gas cell in which a gaseous alkali metal atom is sealed, a first heater to heat the gas cell, and a second heater which is provide to face the first heater across the gas cell and heats the gas cell. The first heater includes a first heating resistor which generates heat by energization, and the second heater includes a second heating resistor through which a current flows in the same direction as the direction of a current flowing through the first heating resistor and which generates heat by energization. Between the first heating resistor and the second heating resistor, a magnetic field generated by the energization to the first heating resistor and a magnetic field generated by the energization to the second heating resistor are mutually cancelled or weakened.

Abstract: An oscillation circuit includes a threshold voltage extraction module, a positive temperature coefficient voltage generation module, an addition module, a common-source amplifier module, a charge and discharge module, and a clock output terminal. The common-source amplifier module includes a first field effect transistor (FET) and a second FET. The addition module includes a first operational amplifier, a second operational amplifier, a third FET, a fourth FET, a fifth FET, a sixth FET, a first resistor, a second resistor, and a third resistor. The charge and discharge module includes a seventh FET, an eighth FET, a charge and discharge FET, a first switch, a second switch, a first comparator, a second comparator, a first nor gate and a second nor gate. An oscillation system is further provided. The oscillation circuit and the oscillation system of the present invention have simple structures and are easy to implement.

Abstract: A method in a mobile communication device includes: measuring a first temperature associated with a crystal configured to provide a reference signal having a frequency; measuring a second temperature associated with a component that is coupled to the crystal by an electrically and thermally conductive line; and compensating, based upon the measuring of the first and second temperatures, for a change in the frequency of the reference signal of the crystal.

Abstract: Methods and apparatus for calibration and temperature compensation of oscillators having mechanical resonators are described. The method(s) may involve measuring the frequency of the oscillator at multiple discrete temperatures and adjusting compensation circuitry of the oscillator at the various temperatures. The compensation circuitry may include multiple programmable elements which may independently adjust the frequency behavior of the oscillator at a respective temperature. Thus, adjustment of the frequency behavior of the oscillator at one temperature may not alter the frequency behavior at a second temperature.

Abstract: An atmosphere temperature at which a quartz-crystal oscillator and an oscillation circuit are placed is controlled in high accuracy, and an output frequency with high stability is obtained. If oscillation outputs of first and second quartz-crystal oscillators are set to f1 and f2, and oscillation frequencies of the oscillation outputs at a reference temperature are set to f1r and f2r, respectively, {(f2?f1)/f1}?{(f2r?f1r)/f1r} is calculated by a frequency difference detection unit. A digital value can be obtained by representing this value by 34-bit digital value, corresponding to a temperature. Therefore, this value is treated as a temperature detection value, a difference with a temperature set value is supplied to the loop filter, and the digital value therefrom is converted into a direct-current voltage to control a heater.

Abstract: An oscillator and a semiconductor integrated circuit device with an internal oscillator capable of compensating the temperature characteristics even when there is a large parasitic capacitance too large to ignore directly between the output terminals of the oscillator. In an oscillator containing an inductance element L, and a capacitive element C, and an amplifier each coupled in parallel across a first and second terminal, the amplifier amplifies the resonance generated by the inductance element and capacitive element and issues an output from the first terminal and the second terminal, and in which a first resistance element with a larger resistance value than the parasitic resistance of the inductance element between the first terminal and the second terminal, is coupled in serial with the capacitive element between the first terminal and the second terminal.

Abstract: A temperature invariant digitally controlled oscillator is disclosed. The digitally controlled oscillator is configured to generate an output clock with stable frequency. The temperature invariant digitally controlled oscillator comprises a digitally controlled oscillator, a temperature sensor, a temperature decision logic circuit, and a temperature conditioner. The digitally controlled signal is provided to adjust the oscillation frequency of the digitally controlled oscillator by changing its capacitances. The stabilization of the silicon temperature is achieved with the temperature sensor, the temperature decision logic circuit, and the temperature conditioner.

Abstract: Circuits, methods, apparatus, and code that provide low-noise and high-resolution electronic circuit tuning. An exemplary embodiment of the present invention adjusts a capacitance value by pulse-width modulating a control voltage for a switch in series with a capacitor. The pulse-width-modulated control signal can be adjusted using entry values found in a lookup table, by using analog or digital control signals, or by using other appropriate methods. The capacitance value tunes a frequency response or characteristic of an electronic circuit. The response can be made to be insensitive to conditions such as temperature, power supply voltage, or processing.

Abstract: A resonator circuit enabling temperature compensation includes an inductor coupled between a first node and a second node of the resonator circuit; a capacitor circuit coupled between the first node and the second node; and a temperature compensation circuit coupled between the first node and the second node. The temperature compensation circuit comprises a varactor coupled to receive a temperature control signal that sets the capacitance of the varactor. A method of generating a resonating output is also disclosed.

Abstract: An electronic device may include a voltage controlled oscillator (VCO) and a temperature sensor. The electronic device may also include a controller configured to cooperate with the VCO and the temperature sensor to determine both a temperature and a frequency error of the VCO for each of a plurality of most recent samples. Each of the most recent samples may have a given age associated therewith. The controller may also be configured to align the temperature, the frequency error, and the given age for each of most recent samples in a three-dimensional (3D) coordinate system having respective temperature, frequency error and age axes. The controller may also be configured to estimate a predicted frequency error of the VCO based upon the aligned temperature, frequency error, and given age of the most recent samples.

Abstract: Disclosed is an oscillator circuit which compensates for external voltage supply, temperature, and a process, includes: a reference voltage generation unit configured to generate reference voltage Vbp stabilized against a change in external voltage supply VDD and temperature; a temperature compensation unit configured to generate first reference voltage PVREF, second reference voltage IVREF, and third reference voltage RX_VREF; an internal voltage supply generation unit configured to generate internal voltage supply VPPI stabilized against the change in external voltage supply VDD and temperature by receiving the first reference voltage PVREF; a current supply unit configured to generate compensation current RX_IREF in proportion to or in inverse proportion to temperature by receiving the second reference voltage IVREF; a process compensation unit configured to perform process compensation by controlling an amount of the compensation current RX_IREF; and an oscillation signal generation unit configured to gen

Abstract: A system and method is provided for controlling frequency of an oscillator. The system includes two or more temperature sensing circuits configured to generate temperature sensing signals corresponding to temperatures obtained by the two or more temperature sensing circuits. The system also includes a reference signal generation circuit configured to generate a reference signal and a first curve function generation circuit coupled to the two or more temperature sensing circuits and the reference signal generation circuit. The first curve function generation circuit is configured to provide two or more curve-generating signals based on the temperature sensing signals and the reference signal. The system further includes a summing circuit coupled to the first curve function generation circuit. The summing circuit is configured to provide, based on the two or more curve-generating signals, a first signal for controlling the frequency of the oscillator.

Abstract: An oscillation device for reducing memory capacity includes a frequency difference detecting unit and a compensation value obtaining unit. When oscillation frequencies of the first and second oscillation circuits are respectively f1 and f2, and oscillation frequencies of the first and second oscillation circuits at a reference temperature are respectively f1r and f2r, the frequency difference detecting unit determines a difference corresponding value x corresponding to a difference value between a value corresponding to a difference between f1 and f1r, and a value corresponding to a difference between f2 and f2r. The compensation value obtaining unit obtains a frequency compensation value of f1 resulting from ambient temperature different from reference temperature based on the difference corresponding value x, and calculates the frequency compensation value of f1 by calculating nth-order polynomial for X being a value corresponding to x/k, where k is a divide coefficient specific to a device.

Abstract: An apparatus and a method for compensating for a mismatch in temperature coefficients of two oscillator frequencies to match a desired frequency ratio between the two oscillator frequencies over a temperature range. In one embodiment of a temperature sensor, first and second oscillators of different temperature characteristics are coupled to a differential frequency discriminator (DFD) circuit. The DFD circuit compensates for the different characteristics in order to match a frequency difference between the first and second frequencies over a temperature range.

Abstract: A temperature-compensated oscillator includes a temperature sensor, a temperature compensation circuit, a voltage-controlled oscillation circuit adapted to output an oscillation signal on which temperature compensation is performed based on the temperature compensation voltage, an output circuit adapted to output an ON/OFF signal based on a relationship between variation of the detected-temperature voltage output by the temperature sensor and a reference voltage, a switch circuit adapted to supply the temperature compensation circuit with electrical power in response to the ON/OFF signal, and a sample-and-hold circuit adapted to be switched between a state of outputting the temperature compensation voltage to the voltage-controlled oscillation circuit while holding the temperature compensation voltage output by the temperature compensation circuit, and a state of outputting the temperature compensation voltage held to the voltage-controlled oscillation circuit while cutting the connection to the temperature c

Abstract: An oscillating signal generator utilized in a phase-locked loop (PLL) includes: an oscillating circuit arranged to generate an oscillating signal according to at least a first control signal; and a control circuit, arranged to adjust the first control signal according to a temperature; and the first control signal is tuned between a first boundary and a second boundary, and when the temperature is closer to a first temperature boundary than a second temperature boundary, and the control circuit is arranged to make the first control signal to be closer to the first boundary than the second boundary such that the oscillating circuit outputs the oscillating signal of a predetermined frequency in a locked mode of the PLL.

Abstract: A method and apparatus for correcting oscillator frequency drift due to crystal aging. Correction signals that reflect a difference between an oscillator timing signal and a reference timing signal over a reference timing signal interval are modeled so that auxiliary correction signals can be generated in the event of loss of the reference timing signal. A temperature curve is generated to model how temperature variation impacts oscillator frequency drift. A rate of frequency drift due to crystal aging is also determined. During loss of a reference timing signal, auxiliary correction signals can be generated to maintain the oscillator at a desired frequency until the reference timing signal becomes available again.

Abstract: One aspect of the present invention includes a reference current generator circuit. The circuit includes a bias circuit configured to generate a reference current along a first current path and a second current along a second current path. The reference current and the second current can be proportional. The circuit also includes a first pair of transistors connected in series and configured to conduct the reference current in the first current path. The circuit further includes a second pair of transistors connected in series and configured to conduct the second current in the second current path. The second pair of transistors can be coupled to the first pair of transistors to provide a collective resistance value of the second pair of transistors that is proportional to temperature.

Abstract: A method of manufacturing a MEMS resonator formed from a first material having a first Young's modulus and a first temperature coefficient of the first Young's modulus, and a second material having a second Young's modulus and a second temperature coefficient of the second Young's modulus, a sign of the second temperature coefficient being opposite to a sign of the first temperature coefficient at least within operating conditions of the resonator. The method includes the steps of forming the resonator from the first material; applying the second material to the resonator; and controlling the quantity of the second material applied to the resonator by the geometry of the resonator.

Abstract: An ovenized micro-electro-mechanical system (MEMS) resonator including: a substantially thermally isolated mechanical resonator cavity; a mechanical oscillator coupled to the mechanical resonator cavity; and a heating element formed on the mechanical resonator cavity.

Abstract: A temperature-compensated oscillator includes a temperature compensation circuit adapted to output a temperature compensation voltage, a voltage-controlled oscillation circuit on which temperature compensation is performed based on the temperature compensation voltage, a switch circuit adapted to perform ON/OFF control on power supply to the temperature compensation circuit, and a sample-and-hold circuit adapted to perform switching control between an ON state of outputting the temperature compensation voltage to the voltage-controlled oscillation circuit while being connected to the temperature compensation circuit and holding the temperature compensation voltage output from the temperature compensation circuit when the power is supplied to the temperature compensation circuit, and an OFF state of outputting the temperature compensation voltage held to the voltage-controlled oscillation circuit while cutting connection to the temperature compensation circuit when the power supply to the temperature compensat

Abstract: A reference circuit for an oscillator module is provided. The reference circuit includes a reference voltage generation unit and a reference current generation unit. The reference voltage generation unit includes an electric element having a voltage proportional to absolute temperature (PTAT voltage) and provides a reference voltage based on the PTAT voltage. The reference current generation unit is coupled to the reference voltage generation unit and provides a reference current to the oscillator circuit to serve as an input current based on the PTAT voltage. The oscillator circuit generates a clock signal based on the reference voltage and the input current. The reference voltage and the input current are proportional to absolute temperature and have the same change trend relative to absolute temperature, such that the clock signal is a temperature insensitive signal. An oscillator module including an oscillator circuit and the foregoing reference circuit is also provided.

Abstract: A value corresponding to a difference value between a value corresponding to a difference between f1 and f1r and a value corresponding to a difference between f2 and f2r is treated as an instantaneous temperature, where f1 and f2 denote oscillation outputs of the first and second oscillation circuits, respectively, and f1r and f2r denote oscillation frequencies of the first and second oscillation circuits, respectively, at a reference temperature. A first correction value is obtained using an approximation formula of the frequency correction value of f1 based on the value corresponding to the difference value, and a second correction value for canceling a correction residual error is obtained from the correction residual error which is a difference between the first correction value and the frequency correction value actually measured. The frequency correction value is obtained from a sum of the first and second correction values.