A vibration device includes a base including a semiconductor substrate and through electrodes that pass through the portion between first and second surfaces of the semiconductor substrate, and a vibrator fixed to the first surface via an electrically conductive joining member. The following components are placed at the second surface: an oscillation circuit that is electrically coupled to the vibrator via the through electrodes and generates an oscillation signal by causing the vibrator to oscillate, a temperature sensor circuit, a temperature compensation circuit that performs temperature compensation on the oscillation signal, and an output buffer circuit that outputs a clock signal based on the oscillation signal. Dsx1<Dbx1, a distance between the output buffer circuit and one of the through electrodes is Dbx1, a distance between the temperature sensor circuit and the other through electrode is Dsx1.

Techniques are described that enables controlling the TNULL characteristic of a self-compensated oscillator by controlling the magnitude and direction of the frequency deviation versus temperature, and thus, compensating the frequency deviation.

A frequency synthesizer is described that includes: a voltage controlled oscillator, VCO; a VCO bias circuit, operably coupled to the VCO and configured to provide a controllable bias current of the VCO; a temperature sensor, located in the frequency synthesizer, configured to determine an operating temperature of the frequency synthesizer; an analog-to-digital converter, ADC, operably coupled to the temperature sensor and configured to provide a digital representation of the determined operating temperature; and a bias control circuit operably coupled and configured to provide a bias control signal to the VCO bias circuit based on the determined operating temperature of the frequency synthesizer. The VCO bias circuit is configured to adjust the controllable bias current applied to the VCO based on the bias control signal.

A frequency synthesizer is described that includes: a voltage controlled oscillator, VCO; a VCO bias circuit, operably coupled to the VCO and configured to provide a controllable bias current of the VCO; a temperature sensor, located in the frequency synthesizer, configured to determine an operating temperature of the frequency synthesizer; an analog-to-digital converter, ADC, operably coupled to the temperature sensor and configured to provide a digital representation of the determined operating temperature; and a bias control circuit operably coupled and configured to provide a bias control signal to the VCO bias circuit based on the determined operating temperature of the frequency synthesizer. The VCO bias circuit is configured to adjust the controllable bias current applied to the VCO based on the bias control signal.

A frequency generator for generating a controlled signal having a controlled frequency uses a frequency ratio generator with an input; a frequency divider for dividing the controlled frequency by a frequency ratio signal to generate a divided signal having a divided frequency; a converter for generating an excitation signal having the divided frequency, the excitation signal exciting a resonator for generating a resonance signal having a resonance frequency; a frequency phase detector of a phase difference between the divided frequency and the resonance frequency; an inner loop filter for generating the frequency ratio signal and filtering the phase difference signal to prevent instability of two frequency ratio generator loops; an output configured for providing the frequency ratio signal based on a ratio between the controlled frequency and the resonance frequency; and a controlled oscillator circuit for generating the controlled signal based on comparison of the frequency ratio with a target ratio.

A semiconductor device including a first inverter circuit connected in parallel to a crystal vibrating element; a second inverter circuit connected to the first inverter circuit so as to share an input therewith, and outputting an oscillation signal; and a wave filter connected to the second inverter circuit and having a passband that is determined in advance and includes an oscillation frequency of the oscillation signal.

A semiconductor device including a first inverter circuit connected in parallel to a crystal vibrating element; a second inverter circuit connected to the first inverter circuit so as to share an input therewith, and outputting an oscillation signal; and a wave filter connected to the second inverter circuit and having a passband that is determined in advance and includes an oscillation frequency of the oscillation signal.

A watch includes a chargeable power supply, a crystal oscillation circuit including a crystal oscillator and an oscillation circuit and configured to stop oscillating when a power supply voltage falls below an oscillation stop voltage and to start oscillating when the power supply voltage exceeds an oscillation start voltage, which is higher than the oscillation stop voltage, and a divider circuit that outputs a reference signal by dividing an oscillation signal output from the oscillation circuit. The watch also includes a temperature compensation circuit that performs a temperature compensation function operation that compensates for variation of the reference signal due to a temperature, a first voltage detection circuit that detects that the power supply voltage exceeded a first voltage that is set higher than the oscillation start voltage, and a control circuit that starts the temperature compensation function operation of the temperature compensation circuit when the first voltage detection circuit detects that the power supply voltage exceeded the first voltage, and subsequently continues the temperature compensation function operation even when the power supply voltage falls below the first voltage.

A watch includes a chargeable power supply, a crystal oscillation circuit including a crystal oscillator and an oscillation circuit and configured to stop oscillating when a power supply voltage falls below an oscillation stop voltage and to start oscillating when the power supply voltage exceeds an oscillation start voltage, which is higher than the oscillation stop voltage, and a divider circuit that outputs a reference signal by dividing an oscillation signal output from the oscillation circuit. The watch also includes a temperature compensation circuit that performs a temperature compensation function operation that compensates for variation of the reference signal due to a temperature, a first voltage detection circuit that detects that the power supply voltage exceeded a first voltage that is set higher than the oscillation start voltage, and a control circuit that starts the temperature compensation function operation of the temperature compensation circuit when the first voltage detection circuit detects that the power supply voltage exceeded the first voltage, and subsequently continues the temperature compensation function operation even when the power supply voltage falls below the first voltage.

A frequency-locked loop (FLL) and a method for correcting an oscillation frequency of an output signal of the FLL are provided. The FLL includes a switched capacitor circuit, a first resistor set, a second resistor set, a determination circuit and a control circuit. The switched capacitor circuit includes a capacitor, and connection of the capacitor is switched according to the oscillation frequency. The first resistor set is configured to provide a first resistance, and the second resistor set is configured to provide a second resistance. The determination circuit is configured to generate a determination result according to the first resistance and the second resistance. The control circuit is configured to generate a control signal for correcting the first resistance and the second resistance according to the determination result, where the oscillation frequency is determined based on the capacitor and at least one of the first resistance and the second resistance.