Abstract: A constant-temperature piezoelectric oscillator includes: a piezoelectric vibrator; an oscillation circuit; a frequency voltage control circuit; a temperature control section; and an arithmetic circuit, wherein the temperature control section includes a temperature-sensitive element, a heating element, and a temperature control circuit, the frequency voltage control circuit includes a voltage-controlled capacitance circuit capable of varying the capacitance value in accordance with the voltage, and a compensation voltage generation circuit, and the arithmetic circuit makes the compensation voltage generation circuit generate a voltage for compensating a frequency deviation due to a temperature difference between zero temperature coefficient temperature Tp of the piezoelectric vibrator and setting temperature Tov of the temperature control section based on a frequency-temperature characteristic compensation amount approximate formula adapted to compensate the frequency deviation, and then applies the voltage t

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: The invention concerns an oscillator generating a wave composed of a frequency of on the order of terahertz from a beat of two optical waves generated by a dual-frequency optical source (10). The oscillator comprises: a modulator (12) the transfer function of which is non-linear for generating harmonics with a frequency of less than one terahertz for each of the optical waves generated by the dual-frequency optical source, an optical detector (14) able to detect at least one harmonic for each of the optical waves generated by the dual-frequency optical source and transforming the harmonics detected into an electrical signal, a phase comparator (15) for comparing the electrical signal with a reference electrical signal, means (16) for controlling at least one element of the dual-frequency optical source with a signal obtained from the signal resulting from the comparison.

Abstract: A resonator-controlled oscillator arrangement comprises a resonator-controlled oscillator of which the operating frequency is adjustable and a control circuit for setting the operating frequency of the oscillator. The control circuit is operative to set the operating frequency in dependence upon prevailing ambient conditions. The control circuit has a control input for initiating a set-up procedure during which the operating frequency of the oscillator is set to a value remote from any resonance frequency of a coupled mode that would cause an activity dip.

Abstract: An oven controlled crystal oscillator includes a thermostatic bath, an inner circuit board, an outer circuit board, a heating element, and a temperature sensor. The inner circuit board comprising a crystal oscillation circuit is positioned inside the thermostatic bath and electrically connected with the outer circuit board via a pin. The outer circuit board has a temperature control circuit and a power supply circuit. The heating element and the temperature sensor electrically connect with the outer circuit board. A through slot is formed through the outer circuit board, and the thermostatic bath is inserted into the through slot. By inserting the thermostatic bath into the through slot of the outer circuit board, the height and the weight of the oven controlled crystal oscillator are reduced, the electric connection performance is enhanced, and thus the stability of the output frequency of the oven controlled crystal oscillator is improved.

Abstract: The present invention relates to an oven controlled crystal oscillator that can obtain stable oscillation frequency by reducing a temperature change in an oscillation element. The oven controlled crystal oscillator comprises; a heat-conducting plate mounted on one surface of a circuit board, a crystal resonator mounted on a surface of the heat-conducting plate opposite to the surface of the circuit board, an oscillation element constituting an oscillation circuit together with the crystal resonator, and a thermistor that detects temperature of the crystal resonator, a heating resistance which heats the crystal resonator, and a temperature control element including at least a power transistor, to constitute a temperature control circuit together with the thermistor and the heating resistance.

Abstract: A crystal resonator comprises a first vibrating region provided on a crystal wafer, a second vibrating region provided on the crystal wafer, the second vibrating region having a different thickness and positive/negative orientation of the X-axis from those of the first vibrating region, and excitation electrodes which are provided respectively on the first vibrating region and the second vibrating region for causing the vibrating regions to vibrate independently. Frequencies that change by different amounts from each other relative to a temperature change can be retrieved from one vibrating region and the other vibrating region. Thus, based on an oscillating frequency of the vibrating region in which a clear frequency change occurs relative to the temperature, the oscillating frequency of the other vibrating region can be controlled. Thereby, increases in the complexity of the crystal oscillator can be suppressed.

Abstract: A temperature compensation method for a piezoelectric oscillator including a piezoelectric vibrator having a frequency temperature characteristic with a hysteresis characteristic, and an oscillation circuit which oscillates the piezoelectric vibrator and outputs an oscillation signal, wherein, to a temperature compensation circuit which can calculate a quantity of temperature compensation using frequency temperature information indicating a temperature characteristic of an oscillation frequency of the piezoelectric vibrator and temperature information of the piezoelectric vibrator at the time of oscillation of the oscillation signal, the oscillation signal and the frequency temperature information are outputted, includes: calculating, as the frequency temperature information, an intermediate value between elevated-temperature frequency temperature information of the piezoelectric vibrator that is generated in the case where ambient temperature of the piezoelectric vibrator is elevated, and lowered-temperature

Abstract: An apparent motion detector is provided with multiple response levels at differing degrees of sensitivity. The motion detector is based on use of a pyroelectric infrared sensor and conventional circuitry which generates an output signal the strength of which reflects transient temperature changes occurring within a field of view and distinguishable from background heat levels. The detector's response varies with the strength of the signal using a plurality of LED's which emit different colors or are driven at different intensities. The system generally will have a field of view defined by a lens system which is translucent to visible light and transparent to infrared. The lens system doubles as a back screen projection system for display of the indicator light.

Abstract: A function generating circuit for producing a control signal for an oscillating circuit that vibrates a crystal unit includes a temperature detecting circuit to detect an ambient temperature, and a Bezier-curve generating circuit to produce a Bezier curve as the control signal in response to the ambient temperature detected by the temperature detecting circuit.

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 disclosed current source circuit includes a current mirror circuit having two enhancement-type MOS transistors, a depletion-type MOS transistor configured to be connected to a drain of one of the two enhancement-type MOS transistors and to function as a constant current source, and a resistor configured to have a negative temperature property and be connected to a source of the one of the two enhancement-type MOS transistors.

Abstract: A component having an acceleration sensor having at least one freely oscillatory mass, and a resonator having at least one resonating structure, in which the at least one freely oscillatory mass of the acceleration sensor and the at least one resonating structure of the resonator are disposed on and/or in one chip. A corresponding production method for a component is also described.

Abstract: Crystal oscillator control and calibration is disclosed. Temperature and frequency control circuits included on a printed circuit board (PCB) comprising a crystal oscillator are used to determine, for each of a plurality of set points in a range of sensed internal temperatures sensed by an internal temperature sensing circuit or device located adjacent to the oscillator in a thermally insulated region of the PCB, a corresponding compensation required to be applied to maintain a desired oscillator output frequency. The PCB is configured to use at least the determined compensation values and a sensed internal temperature to determine during operation of the PCB a compensation, if any, to be applied to maintain the desired oscillator output frequency.

Abstract: A voltage controlled oscillator having a temperature and process controlled output. A VCO in accordance with the present invention comprises a reference current source, a fixed current source, coupled in series with the reference current source, the fixed current source comprising a temperature independent current source, a third current source, coupled in parallel with the combination of the reference current source and the fixed current source, and an oscillator, coupled in series with the third current source, wherein a current used to control the oscillator is based on operating temperatures and processes of the reference current source and the third current source.

Abstract: A circuit may comprise an amplifier powered by a first supply voltage, with a first input of the amplifier coupled to a stable reference voltage, and the output voltage of the amplifier provided as a designated supply voltage to an oscillator configured to produce a periodic signal having a specified frequency. The circuit may further include a control circuit coupled to a second input of the amplifier, to the output of the amplifier, and to ground, and configured to control the rate of change of the output voltage of the amplifier with respect to temperature. This rate of change may be specified according to a characterization of the oscillator over supply voltage and temperature, and may result in stabilizing the specified frequency across temperature. The periodic signal may therefore be unaffected by variations in the first supply voltage, and the amplitude of the periodic signal may be proportional to the stable reference voltage.

Abstract: A thermostatic-chamber temperature control device includes: a heating element for heating a thermostatic chamber; a bridge circuit having a temperature sensitive element whose resistance value varies in accordance with the temperature of the heating element; a detection circuit for detecting an unbalanced voltage of the bridge circuit; a PWM signal generating circuit for generating a PWM signal corresponding to the unbalanced voltage detected by the detection circuit; and a switching element that has a current output terminal connected to the heating element and a current input terminal connected to a power supply circuit and is driven on the basis of the PWM signal generated by the PWM signal generating circuit.

Abstract: A resonator having an effective spring constant (kz) and comprising a beam having a beam spring constant (kB) adapted to resonate in an oscillation direction, and extending at a non-zero angle (?) to the oscillation direction, wherein the resonator has a predetermined geometry and is formed from one or more materials, the or each material having a coefficient of thermal expansion (CTE), the CTE of the or each material together with the predetermined geometry of the resonator causing ? to vary with temperature, such that the temperature dependence of the beam spring constant is compensated for, resulting in the effective spring constant of the resonator remaining substantially constant within an operating temperature range.

Abstract: Aspects of a method and system for an energy efficient temperature sensing crystal integrated circuit (TSCIC) are provided. In this regard, one or more circuits in a temperature sensing crystal integrated circuit (TSCIC) may be configured to control power consumption of the TSCIC. The one or more circuits in the TSCIC may comprise a memory and a crystal. The one or more circuits in the TSCIC may be operable to generate an indication of temperature of the crystal. The one or more circuits in the TSCIC may be configured to control a current supplied to the crystal within the TSCIC, wherein the configuring is based on phase noise requirements of a signal generated by the crystal. Generation of the temperature indication may be enabled or disabled. The enabling or disabling may occur based on a rate of change of a temperature in the TSCIC.

Abstract: A temperature controlled oscillator is provided with a circuit substrate having a crystal resonator, an oscillating circuit, and a temperature control circuit, arranged on one or both principal surfaces, and a container main body that accommodates the circuit substrate and has mount terminals on an outer bottom surface thereof. The temperature control circuit includes at least a first temperature sensor that detects an operating temperature of the crystal resonator, a second temperature sensor that detects a surrounding temperature of the container main body, and a heating resistor that applies heat to the crystal resonator, and lead wires extend from the circuit substrate and are connected electrically to the mount terminals. An insulation groove that passes through the circuit substrate in a thickness direction is formed between: a first lead wire closest to the second temperature sensor, and the second temperature sensor; and the heating resistor.

Abstract: Mechanical resonating structures are described, as well as related devices and methods. The mechanical resonating structures may have a compensating structure for compensating temperature variations.

Abstract: Techniques of compensating frequency in an output in reference to a reference frequency signal are disclosed. The reference frequency signal may be from a crystal oscillator or other oscillators. Due to the changes of the temperature, the reference frequency signal drifts. According to one aspect of the techniques, a temperature frequency correction word is generated in accordance with a frequency compensation value in view of a current temperature to generate a substantially temperature compensated frequency output from a reference frequency signal. The frequency control word is produced from a successive approximation circuit configured to produce the temperature frequency correction word in accordance with the frequency compensation value in view of the current temperature. Both the temperature frequency correction word and a frequency control word are data represented in a sequence of bits. As a result, the compensated frequency output can be of high precision.

Abstract: A temperature-compensated-resistance (TCR) circuit, which may be part of an integrated circuit, is provided. The TCR circuit consists of two resistors and a diode. The two resistors are connected in parallel and the diode is connected in series with one of the resistors. The two parallel legs of the TCR circuit may be connected to a reference voltage source, such as a ground. No specialized devices, such as bipolar transistors, Zener or Schottky diodes, or specially-processed resistors, are required by the TCR circuit. The resistors and the diode of the TCR circuit may be chosen to adjust for temperature variations in the resistance values of the resistor, leading to a negative, zero, or positive temperature coefficient of resistance for the circuit. A phase-locked loop (PLL) circuit is described as an application of the TCR circuit.

Abstract: The invention discloses a PVT-independent current-controlled oscillator, including a PV-controller, a current-controlled oscillator and a T-controller. The current-controlled oscillator is coupled to the PV-controller and outputs an oscillation frequency.

Abstract: A periodic signal generating circuit which is dependent upon temperature for establishing a temperature independent refresh frequency is presented. The periodic signal generating circuit includes a reference voltage generating unit and a periodic signal generating unit. The reference voltage generating unit produces a reference voltage which exhibits a variable voltage level in response to temperature. The periodic signal generating unit produces a periodic signal in response to a set voltage to determine the reference voltage and an oscillation period, wherein a transition timing of the set voltage is controlled by the reference voltage. As a result the periodic signal has a relatively constant period which can be produced regardless of the temperature variation.

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: 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 present invention is a Chip Scale Atomic Clock (CSAC)-enabled Time and Frequency Standard (CTFS) architecture. The CTFS architecture includes a microcontroller, a Time Compensated Crystal Oscillator (TCCO) circuit which is connected to the microcontroller, and a Chip Scale Atomic Clock (CSAC) which is connected to the microcontroller. The microcontroller is configured for selectively causing the CTFS to provide a TCCO circuit-based output frequency when the CTFS has not locked to a predetermined atomic resonance, and is further configured for causing the CTFS to provide a CSAC-based output frequency when the CTFS has locked to a predetermined atomic resonance.

Abstract: The objects of the present invention are to shorten a cavity length of an optoelectronic oscillator and to integrate on a semiconductor or SiO2-substrate. An optoelectronic oscillator 10 have an optoelectronic loop comprising a semiconductor laser 11, an optical waveguide 12 guiding laser light emitted from the semiconductor laser, a photodetector 13 detecting laser light guided by the optical waveguide and outputting an electrical signal, an amplifier 14 amplifying the electrical signal outputted from the photodetector, generating an amplified signal and formed on a semiconductor substrate 15. Laser light emitted from the semiconductor laser 11 is controlled by generated amplified signal and it oscillates with a fundamental oscillation frequency determined by a delay time of carrier in the optoelectronic loop circuit or one of the high harmonic components of integral multiples of a fundamental oscillation frequency.

Abstract: An oscillator assembly including an oscillator seated on a pad of thermally conductive material formed on the surface of a printed circuit board and covered by a lid defining an oven for the oscillator. In one embodiment, a plurality of heaters are located on different sides of the oscillator and at least partially seated on the pad for evenly transferring heat to the pad and the oscillator. In one embodiment, the oscillator is a temperature compensated crystal oscillator and an integrated amplifier controller circuit on the printed circuit board integrates at least one operational amplifier for controlling the heater(s) and one or more transistors for providing heat to the oven. A canopy seated on the pad and covering the oscillator can be used for transferring heat more evenly to the oscillator. A cavity in the bottom of the printed circuit board defines an insulative air pocket.

Abstract: A constant-temperature type crystal oscillator includes: a crystal unit that is installed on one principal surface of a circuit substrate, and chip resistors, which function as heating elements, and which are installed on the other principal surface of the circuit substrate so as to face a principal surface of the crystal unit, the chip resistors heating up the crystal unit to keep an operational temperature of the crystal unit constant. A heating metal film facing the principal surface of the crystal unit is provided on the one principal surface of the circuit substrate. A heat conducting material is interposed between the principal surface of the crystal unit and the heating metal film to perform thermal coupling therebetween. The heating metal film is thermally coupled to electrode terminals of the chip resistors via a plurality of electrode through holes.

Abstract: An electronic device is equipped with an oscillator interface to be coupled to an oscillator crystal of an oscillator element. The electronic device includes an oscillator circuit which is coupled to the oscillator interface and generates an oscillator signal. The electronic device is further provided with a temperature measurement interface to be coupled to a temperature sensor of the oscillator element so as to receive the temperature signal. For accomplishing temperature compensation, the electronic device is provided with a measurement controller coupled to the measurement interface and configured to measure a first value of the temperature signal at a first point of time and a second value of the temperature signal at a second point of time. A frequency drift estimator is provided so as to estimate a frequency drift of the oscillator signal on the basis of the first value of the temperature signal and a second value of the temperature signal.

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: There is provided with a resonator which can correct the resonance frequency of a vibrator in a wide range and with a high accuracy and also provided with an oscillator using the resonator. In the resonator configured by the vibrator 101, electrodes 4, 5 disposed so as to oppose to parts of the surface of the vibrator 101 via gaps, and variable voltage sources 24, 25 for applying a voltage to both or one of the vibrator 101 and the electrodes 4, 5, each of the electrodes 4, 5 is configured by plural electrodes. The electrodes 4, 5 are respectively disposed via gaps close to the portions of the vibrator 101 having different vibration amplitudes. The DC voltages being applied are independently adjusted with respect to the electrodes 4, 5 which differ in distances from the shaft of the vibrator among the plural electrodes close to the vibrator 101.

Abstract: There is provided a temperature compensated piezoelectric oscillator which excels in frequency stability and has a good electronic noise characteristic, and with which a circuit can be structured simply. An auxiliary oscillator unit 21 sharing a crystal substrate 2 with a main oscillator unit 11 outputting a set frequency f0 to an outside is used as a temperature detecting unit 32 detecting a temperature T for obtaining a compensation voltage ?V in a temperature compensated piezoelectric oscillator (TCXO), and electrodes 13, 23 of the main oscillator unit 11 and the auxiliary oscillator unit 21 are provided separately on the crystal substrate 2. For example, a fundamental wave and an overtone are used or a thickness shear vibration and a contour shear vibration are used in the main oscillator unit 11 and the auxiliary oscillator unit 21, respectively.

Abstract: Embodiments of a phase lock loop and a method for compensating a temperature thereof can output an initial tuning digital value for a voltage controlled oscillator configured to output a desired phase lock loop frequency compensated according to a temperature change. Embodiments of a phase lock loop and a method for compensating a temperature thereof can simultaneously perform a digital coarse tuning and an analog fine tuning to compensate for a temperature in a limited time.

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: Systems and methods are disclosed herein for using a switched mode TCXO or VC-TCXO in a satellite navigation receiver 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 satellite acquisition 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 satellite tracking performance is sensitive to discontinuities in the phase, frequency, and/or frequency rate of the oscillator clock when temperature compensation is applied.

Abstract: The present invention relates to an inductive proximity switch with an oscillator having a resonant circuit and an amplifier and with an evaluating and control device for evaluating an impedance of the resonant circuit and for outputting a switching signal. According to the invention, the proximity switch is characterized in that a frequency measuring device is provided for measuring the oscillation frequency of the oscillator and for eliminating ambiguities of the evaluation result of the evaluating and control device. The invention also relates to a method for operating an inductive proximity switch.

Abstract: An oscillator device for generating an oscillator signal, includes a heater arrangement, a first switching element, a temperature sensor, signal process means, and voltage controlled oscillator; an output of the temperature sensor being connected to an input of the signal processing means, and an output of the signal processing means being connected to an input of the voltage controlled oscillator. The first switching element is arranged for receiving the oscillator signal from the voltage controlled oscillator and for providing a heater drive signal to either a first heater element or a second heater element of the heater arrangement based on the oscillator signal. The signal processing means comprise a synchronous demodulator.

Abstract: Example embodiments of the present invention are 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. 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. 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: A speed monitor circuit integrated in an integrated circuit (IC) determines the speed of the IC. The speed monitor circuit includes an oscillator that generates an oscillator signal. A speed determining circuit generates a first count based on transitions of the oscillator signal. A match signal corresponds to the speed of the oscillator based on the first count and a reference count.

Abstract: A method and apparatus for real time clock brownout detection. A low power real time clock (RTC) operates continuously to keep time in a global positioning system (GPS) receiver while some receiver components are powered down. In various embodiments, a brownout detector circuit detects a loss of RTC clock cycles. If a loss of RTC clock cycles exceeds a predetermined threshold such that the RTC is not reliable for GPS navigation, an RTC status signal so indicates.

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 modulation-signal generating circuit includes a temperature monitoring unit that detects a casing temperature of the circuit, a voltage control oscillator including two variable impedance circuits that independently control oscillation frequency based on an input control voltage, a frequency-correction-voltage generating unit that outputs a voltage for compensating for a temperature drift of an oscillation frequency according to the casing temperature detected by the temperature monitoring unit, to one of the variable impedance circuits, and an FM-modulation-voltage generating unit that outputs a modulation voltage containing a constant DC component not depending on temperature and a predetermined AC component, to the other variable impedance circuit, under a temperature drift compensation condition of the frequency-correction-voltage generating unit.

Abstract: An integrated circuit is used to monitor and process parametric variations, such as temperature and voltage variations. An integrated circuit may include a temperature-sensitive oscillator circuit and a temperature-insensitive oscillator circuit, and frequency difference between the two sources may be monitored. In some embodiments, a parametric-insensitive reference oscillator is used as a reference to measure frequency performance of a second oscillator wherein the second oscillator performance is parametric-sensitive. The measured frequency performance is then compared to a tamper threshold and the result of the comparison is indicative of tampering.

Abstract: The present invention relates to an integrated circuit for a temperature compensated crystal oscillator having an external crystal. The integrated circuit comprises a temperature compensation having one fixed or at least two selectable 3rd and/or 4th and/or 5th and/or higher order temperature compensation functions for at least one specific type of external crystal. The temperature compensation can be calibrated at one temperature, in other words without use of temperature variation, by means of an external voltage or current source overdriving a respective temperature-dependent voltage or current supplied from an internal temperature sensor to the temperature compensation.

Abstract: A temperature compensated oscillation circuit capable of providing a stable frequency output over temperature is provided, in which an oscillator with a crystal resonator is arranged to generate an oscillation signal with an output frequency, and a temperature sensor provides a temperature compensation voltage of which a function is linear with respect to an ambient temperature of the oscillator. A first accumulation mode MOS varactor is coupled to the oscillator, and the first accumulation mode MOS varactor adjusts a capacitance thereof in response to the temperature compensation voltage, such that the coupled oscillator has a frequency compensation over temperature for the oscillation signal, wherein the frequency compensation substantially varies as an inverse function of a deviation of the crystal resonator over temperature when the ambient temperature is within a predetermined temperature range.

Abstract: A voltage reference connects to a voltage-to-current converter to generate a reference current dependent on the reference voltage. Outputs of a toggle-type flip flop connect to switching transistors controlling the reference current charging capacitors. The toggling of the flip-flop is controlled by comparing the capacitor voltages to the reference voltage, such that the toggle frequency is proportional to the time charging the capacitors. Optionally, temperature compensation data, representing a magnitude and direction rotation of the frequency versus temperature characteristic is stored and, based on a sensed temperature, retrieved to modify the reference current.

Abstract: An inventive temperature-compensated crystal oscillator has a construction such that a crystal oscillator element (5) is accommodated in a container (1) and an IC element (7) for controlling an oscillation output on the basis of the oscillation of the crystal oscillator element (5) is mounted on a lower surface of the container (1). A plurality of electrode pads (10) at least including plural crystal electrode pads connected to the crystal oscillator element (5), plural writing control electrode pads, and an oscillation output electrode pad, a ground electrode pad, a power source voltage electrode pad and an oscillation control electrode pad connected to surface mounting external terminals are arranged in a matrix configuration of m rows×n columns (wherein m and n are natural numbers not smaller than 2) in an IC element mounting area. The IC element (7) is electrically connected to the electrode pads (10).