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 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: An integrated circuit includes a delay lock loop (DLL) circuit that generates incremental delay line signals and a delay line output signal based on a received clock signal. A pulse-width modulation (PWM) control module generates a PWM control signal. A tunable circuit having variable capacitance is controlled based on the delay line output signal, the PWM control signal, and one of the incremental delay line signals.

Abstract: A crystal oscillator emulator integrated circuit includes a first temperature sensor configured to sense a first temperature of the crystal oscillator emulator integrated circuit. The memory is configured to (i) store calibration parameters and (ii) select at least one of the calibration parameters based on the first temperature. A semiconductor oscillator is configured to generate an output signal, wherein (i) the output signal has a frequency and an amplitude and (ii) the frequency is based on the at least one of the calibration parameters. An amplitude adjustment module is configured to (i) compare the amplitude to a predetermined amplitude and (ii) generate a control signal to adjust the amplitude based on the comparison.

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 refresh period signal generator with a digital temperature information generation function includes a temperature information generating part configured to generate temperature information by using a first period signal and a second period signal, a refresh period signal generating part configured to output a refresh period signal by selecting one signal having a shorter period between the first period signal and the second period signal, and an operation timing control part operating the temperature information generating part and the refresh period signal generating part at a predetermined timing.

Abstract: A digitally controlled frequency generator includes an oscillator module for generating a first clock signal having an oscillating frequency, a programmable control module operable so as to generate a control signal corresponding to a desired frequency, and a direct digital frequency synthesizer coupled to the oscillator module and the programmable control module for receiving the first clock signal and the control signal therefrom, and for generating a second clock signal having the desired frequency based on the first clock signal from the oscillator module and the control signal from the programmable control module.

Abstract: An oscillator circuit includes a combination of two frequency-determining elements, designed as single-port surface wave resonators with interdigital converters, and one active electronic circuit. The two single-port surface wave resonators are connected to each other, avoiding inductive components. In the case of a combination in a parallel circuit, the connection is designed as a combination oscillating at high-frequency anti-resonance, and in the case of a combination in a series circuit, the combination is designed as a combination oscillating at high-frequency resonance.

Abstract: A method for manufacturing a quartz crystal unit comprises forming a quartz crystal tuning fork resonator that is capable of vibrating in a flexural mode of an inverse phase and that has a quartz crystal tuning fork base, and first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base. An electrode is disposed on each of two of side surfaces of each of the first and second quartz crystal tuning fork tines so that the electrodes of the first quartz crystal tuning fork tine have an electrical polarity opposite to an electrical polarity of the electrodes of the second quartz crystal tuning fork tine, a motional capacitance C1 of a fundamental mode of vibration of the quartz crystal tuning fork resonator being greater than a motional capacitance C2 of a second overtone mode of vibration thereof.

Abstract: A control apparatus and method for controlling an image display includes at least one reference object for generating a predetermined spectrum signal, a modulation unit for modulating the predetermined spectrum signal with a predetermined method, and a remote controller. The remote controller includes an image sensor for receiving the modulated predetermined spectrum signal and generating a digital signal and a processing unit for receiving the digital signal, demodulating the digital signal, and calculating an image variation of the image of the reference object formed on the digital image.

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: A clock synthesis circuit includes a delta sigma modulator that receives a divide ratio and generates an integer portion and a digital quantization error (a fractional portion). A fractional-N divider divides a received signal according to a divide control value corresponding to the integer portion and generates a divided signal. A phase interpolator adjusts a phase of the divided signal according to the digital quantization error to thereby reduce noise associated with the fractional-N divider.

Abstract: A frequency-control circuit, which is configured to receive a first signal having a first untuned frequency from a first oscillator, and to alter one or more pulses of the first signal to tune an output frequency of an output clock signal to have an average frequency at the desired target frequency. In some embodiments, the frequency-control circuit receives a signal from a single oscillator to generate a calibrated, precise, and temperature-stable clock.

Abstract: A VCO driving circuit and a frequency synthesizer wherein the impedance viewed from a VCO control terminal is reduced to prevent the VCO phase noise characteristic from degrading. A VCO driving circuit and a frequency synthesizer having the VCO driving circuit, which comprises a coarse adjustment DAC that receives a digital data, which has a coarse adjustment frequency, to output an analog signal; a fine adjustment DAC that receives a digital data, which has a fine adjustment frequency, to output an analog signal; a low response speed LPF5 that removes noise from the output signal from the coarse adjustment DAC and then provides the resultant signal as an input to a VCO control terminal; a high response speed LPF7 that converts the output signal from the fine adjustment DAC to a voltage, thereby smoothing the signal; a resistor that connects an input stage of the LPF5 to that of the LPF7; and a capacitor used for providing a capacitive coupling such that the output of the LPF7 is added to that of the LPF5.

Abstract: A temperature compensated crystal oscillator is mounted to a board. A quartz resonator includes a quartz chip that generates an oscillation frequency. A resistive element is formed on the quartz chip. A temperature sensor is located closer to the board than the quartz resonator. The compensation part compensates for a change in the oscillation frequency generated by the quartz resonator based on a value of a current flowing in the resistive element and an output of the temperature sensor.

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: An integrated circuit package comprises an integrated circuit that comprises a temperature sensor that senses a temperature of the integrated circuit. A memory module stores oscillator calibrations and selects one of the oscillator calibrations as a function of the sensed temperature. An oscillator module generates a reference signal having a frequency that is based on the selected one of the oscillator calibrations. An epoxy layer adheres a glass layer to the integrated circuit. A packaging material encases at least part of the glass layer and the integrated circuit.

Abstract: A temperature-compensated crystal oscillator includes a mode selector circuit 100, a control logic serial•interface 200, a PROM circuit 300, an oscillation control circuit 400 and an oscillation circuit 500, and has, as terminals, a power terminal (VCC/CLK) 11, an input terminal (VC/DATA/PE) 12, an output terminal (OUT) 13 and a ground terminal (GND) 14. The mode selector circuit 100 switches the crystal oscillator to an emulation mode when a first signal in which a power voltage and a clock signal supplied through the power terminal 11 are superimposed, is inputted from the power terminal and a second signal having a predetermined pattern is inputted from the input terminal 12.

Abstract: A ring oscillator includes an odd number of unit circuits connected in series each of which includes an inverter. Each of the unit circuits includes the inverter and a MOSFET. The MOSFET is an FET which is a temperature sensor, and uses a drain-source leakage current in a state that the FET is normally turned off.

Abstract: A self-calibrating temperature compensated oscillator includes a monolithic structure having a first resonator, a second resonator, and a heating element to heat the first and second resonators. The temperature coefficient of the second resonator is substantially greater than the temperature coefficient of the first resonator. A first oscillator circuit operates with the first resonator and outputs a first oscillator output signal having a first oscillating frequency. A second oscillator circuit operates with the second resonator and outputs a second oscillator output signal having a second oscillating frequency. A temperature determining circuit determines the temperature of the first resonator using the second oscillating frequency. A temperature compensator provides a control signal to the first oscillator in response to the determined temperature to adjust the first oscillating frequency and maintain it at a desired operating frequency.

Abstract: Method and systems are provided for adjusting real-time clocks to compensate for frequency offset, temperature effects, and/or aging effects.

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: Timing calibrator is disclosed. A first oscillator includes an output. The first oscillator includes a mechanically resonant element. A second oscillator includes an output. The second oscillator includes a quartz resonator. A frequency relater has an output, a first input, and a second input. The frequency relater has the first input coupled to the first oscillator output and the second input coupled to the second oscillator output.

Abstract: An integrated circuit comprises a microelectromechanical (MEMS) resonator circuit that generates a reference frequency. 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. A phase locked loop module receives the reference signal, comprises a feedback loop having a feedback loop parameter and selectively adjusts the feedback loop parameter based on the at least one of the calibration parameters.

Abstract: An interleaved voltage-controlled oscillator (VCO) is disclosed. The VCO includes a ring circuit comprising a series connection of main logic inverter gates, a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates, at least one temperature compensation circuit comprising a logic inverter gate in series connection with one or more field effect transistors, the field effect transistor responsive to a compensating voltage input that is proportional to temperature, and an electronic circuit in signal communication with the at least one temperature compensation circuit and configured to provide a voltage signal responsive to temperature. Each delay element includes a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages, and a proportional section, comprising controls for regulating signal transmission through at least one logic inverter gate.

Abstract: An apparatus for providing oscillator frequency stability is disclosed. The apparatus includes an internally ovenized oscillator module having an oscillator and an inner heater to maintain the oscillator at a first temperature during operation. The apparatus also includes a thermally conductive cover for forming a first compartment to contain the internally ovenized oscillator module along with multiple heaters. The heaters are in thermal communication with the thermally conductive cover and the substrate to form an oven to keep the internally ovenized oscillator module at a stable second temperature during operation. In addition, the apparatus includes a thermally insulative cover for forming a second compartment to contain the first compartment.

Abstract: An interleaved voltage-controlled oscillator (VCO) is disclosed. The VCO includes a ring circuit comprising a series connection of main logic inverter gates, a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates, at least one temperature compensation circuit comprising a logic inverter gate in series connection with one or more field effect transistors, the field effect transistor responsive to a compensating voltage input that is proportional to temperature, and an electronic circuit in signal communication with the at least one temperature compensation circuit and configured to provide a voltage signal responsive to temperature. Each delay element includes a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages, and a proportional section, comprising controls for regulating signal transmission through at least one logic inverter gate.

Abstract: An oscillator having improved frequency stability which includes an oscillator circuit and an SC-cut resonator connected with the oscillator circuit. The SC-cut resonator has a first turning point. A temperature compensation circuit is connected with the oscillator circuit. The temperature compensation circuit is adapted to adjust a reference frequency generated by the oscillator circuit according to a frequency response associated with a second turning point of an AT-cut resonator.

Abstract: A technique for reducing temperature sensitivity of an LC oscillator circuit includes a passive circuit coupled in parallel with a load capacitor. In at least one embodiment, an oscillator circuit is configured to generate a periodic signal having a free-running frequency. The oscillator circuit includes a first circuit portion including at least one inductor coupled in parallel with at least one load capacitor. The first circuit portion has an inductance-capacitance product that has a first temperature sensitivity. The oscillator circuit includes a passive circuit portion coupled in parallel with the first circuit portion. The passive circuit portion includes at least one resistor in series with at least one capacitor. The passive circuit portion has a second temperature sensitivity that opposes an effect of the first temperature sensitivity on the free-running frequency of the oscillator circuit, thereby reducing temperature sensitivity of the free-running frequency.

Abstract: A clock generator has a ring oscillator which has odd-numbered inverters connected in series, wherein an output of the inverter at a final stage is inputted into the inverter at a first stage to generate and output a clock signal, a frequency divider which receives the clock signal outputted from the ring oscillator, and divides frequency thereof for output, and a heater which is on-off controlled based on the output of the frequency divider and heats the ring oscillator when turned on.

Abstract: A crystal oscillator emulator integrated circuit, comprises a first temperature sensor that senses a first temperature of the integrated circuit; memory that stores calibration parameters and that selects at least one of the calibration parameters based on the first temperature; a semiconductor oscillator that generates an output signal having a frequency that is based on the calibration parameters; and an adaptive calibration circuit that adaptively adjusts a calibration approach for generating the calibration parameters based on a number of temperature test points input thereto.

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: A divider control circuit includes a first and a second delta sigma modulator configured to generate a divider control signal for a fractional-N divider and a fractional signal indicative of a phase error in the divider output. The fractional signal is supplied for control of an interpolator circuit. The divider control circuit may be implemented as a look-ahead circuit where two or more divider control signals and fractional signals are generated during a single cycle to allow the divider control circuit to be run at a reduced clock rate.

Abstract: A system and method include receiving an external reference signal and generating first temperature control commands to maintain a constant ambient temperature for a crystal oscillator using a first temperature control system. The method further includes generating second temperature control commands for a second temperature control system to establish a desired ambient temperature for the crystal oscillator according to a temperature training profile. While at least one of the first and second temperature control systems operates to change an ambient temperature, the method includes extracting a clock from the external reference signal, generating a correction signal to further generate a corrected oscillation based on a difference between the extracted clock and the crystal oscillator and training an adaptive control algorithm based on the correction signal in relation to a determined crystal oscillator response to temperature variations caused by the second temperature control system.

Abstract: A frequency-control circuit, which is configured to receive a first signal having a first untuned frequency from a first oscillator, and to alter one or more pulses of the first signal to tune an output frequency of an output clock signal to have an average frequency at the desired target frequency. In some embodiments, the two oscillators of intentionally different frequencies are periodically switched at a duty factor, which is dependent on an absolute temperature, to generate a calibrated, precise, and temperature-stable clock.

Abstract: An integrated circuit comprises a film bulk acoustic resonator (FBAR) circuit that generates a reference frequency. 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. A phase locked loop module receives the reference signal, comprises a feedback loop having a feedback loop parameter and selectively adjusts the feedback loop parameter based on the at least one of the calibration parameters.

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 that is based on the calibration parameters. A heater adjusts the first temperature to a predetermined temperature. A disabling circuit disables the heater after the calibration parameters are stored in the memory.

Abstract: A signal generation technique is based on a reference frequency provided by a MEMS resonator. The signal generation technique compensates for temperature- and fabrication process-induced frequency variations collectively. In some embodiments, a device implementing the disclosed signal generation technique includes a fractional-N synthesizer, a temperature sensor, calibration data, and a sigma-delta modulator to adjust the reference frequency of the MEMS resonator to a desired frequency value while compensating for the temperature variation of the MEMS resonator.

Abstract: Provided is an oscillating device, which can adjust the oscillation angle and the phase of a movable plate easily with a simple constitution. A light scanning device acting as the oscillating device comprises a mirror element for oscillating the movable plate having a mirror film, a control circuit having a duty ratio adjusting unit and a function to change the duty ratio of the pulse voltage, so that it applies the pulse voltage thereby to drive a vertical comb of the mirror element, and an oscillation detecting unit for detecting the oscillations of the movable plate. On the bases of the movable plate oscillations detected by the oscillation detecting unit, the control circuit controls the duty ratio adjusting unit thereby to change the duty ratio of the pulse voltage.

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 temperature detector circuit using a MOS transistor capable of reducing manufacture variation of a mobility and realizing stable output characteristics which are not affected by temperature dependency may be offered. In one example, the temperature detector circuit includes a pair of depression type transistors to output a voltage which is proportional to temperature from a connecting point of a source of a first transistor and a drain of a second transistor. The transistors are the same conducted type of current and are formed in different channel size, which are connected between power supplies in series, and have a configuration in which first transistor's gate and source are connected each other and a first transistor's drain is connected with a second power supply and second transistor's gate and drain are connected each other and a second transistor's source is connected with a first power supply.

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: Mechanisms are provided for compensating for process and temperature variations in a circuit. The mechanisms may select at least one resistor in a plurality of resistors in the circuit to provide a resistance value for generating a calibration voltage input to the circuit to compensate for variations in process. A reference signal may be compared to a feedback signal generated by the circuit based on the calibration signal. A determination is made as to whether the feedback signal is within a tolerance of the reference signal and, if so, an identifier of the selected at least one resistor is stored in a memory device coupled to the circuit. The circuit may be operated using the selected at least one resistor based on the identifier stored in the memory device. An apparatus and integrated circuit device utilizing these mechanisms are also provided.

Abstract: Oscillator devices and methods of operating such oscillator devices are disclosed. The oscillator devices include a current source, and an oscillation module to provide a clock signal. The frequency of the clock signal depends on the relationship between a threshold voltage of a transistor at the oscillation module and the current level provided by the current source. The transistor at the oscillation module is matched to a transistor at the current source so that the frequency of the clock signal is relatively insensitive to changes in device temperature.

Abstract: Embodiments of determining power to be supplied to the load using an expected voltage decrease that would result from supplying power to the load are disclosed.

Abstract: Techniques for voltage controlled oscillator (VCO) circuits that are independent of temperature and process variations are described herein.

Abstract: A power supply circuit includes a first voltage regulator to generate a first supply voltage for a first circuit of a phase-locked loop and a second voltage regulator to generate a second supply voltage for a second circuit of the phase-locked loop. The first and second supply voltages are independently generated by the first and second voltage regulators based on the same reference signal. The first circuit may be a charge pump and the second circuit may be a voltage-controlled oscillator. Different circuits may be supplied with the independently generated supply voltages in alternative embodiments.

Abstract: A calibration circuit (20, 50) and method (60) for calibrating the bias current of a VCO (10, 40) to minimize phase noise. The calibration circuit (20, 50) monitors the average voltage at the common-mode node of the VCO (10, 40) while varying the bias current over a predetermined range. The calibration circuit (20, 50) identifies the bias current associated with the minimum average common-mode voltage and utilizes this bias current for calibrating the biasing transistor of the VCO (10, 40).

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: A temperature detection circuit (18) detects temperature around an oscillation circuit (20) equipped with voltage variable capacitors (23, 24). According to its temperature detection signal, a temperature compensation circuit (30) produces a voltage signal as a temperature compensation signal. That voltage signal is supplied to the voltage variable capacitors (23, 24) in order to sustain oscillation frequency of the oscillation circuit (20) at a substantially constant level. When a switch element (1) is, turned on by a non-TCXO signal, both terminals of each voltage variable capacitor (23, 24) are brought to the same potential (ground potential). Consequently, each voltage variable capacitor has a predetermined capacitance and temperature compensation function is made ineffective. In that state, initial frequency regulation is performed under normal temperature.