An oscillator includes: an outer package; an inner package accommodated in the outer package and fixed to the outer package via a heat insulating member; a vibration element accommodated in the inner package; a temperature sensor; a first circuit element accommodated in the inner package and including an oscillation circuit configured to oscillate the vibration element and generate a temperature-compensated oscillation signal based on the temperature sensor; and a second circuit element fixed to the outer package and including a frequency control circuit configured to control a frequency of the oscillation signal.

An integrated circuit apparatus includes an oscillation circuit that generates an oscillation signal by using a resonator, an output buffer circuit that outputs a clock signal based on the oscillation signal, a DC voltage generation circuit that generates a DC voltage used to generate the oscillation signal or the clock signal, a power source pad to which a power source voltage is supplied, a ground pad to which a ground voltage is supplied, and a clock pad via which the clock signal is outputted. The ground pad and the DC voltage generation circuit are disposed so as to overlap with each other in the plan view.

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 time synchronization device adapted for an electronic apparatus, an electronic apparatus, a time synchronization system and a time synchronization method. The time synchronization device includes: a signal generating circuit and a time adjusting circuit. The signal generating circuit includes: a control circuit, configured to generate a frequency control word; and a signal adjusting circuit, configured to receive the frequency control word and an input signal having an initial frequency, and to generate and output an output signal having a target frequency based on the frequency control word and the input signal. The time adjusting circuit is configured to perform a synchronization adjusting operation on a clock signal of the electronic apparatus based on the output signal having the target frequency.

A temperature compensated oscillator circuit includes a first oscillator, a second oscillator, a first divider, a second divider, a frequency ratio circuit, and a temperature compensation circuit. The first divider is coupled to the first oscillator, and is configured to divide a frequency of a first oscillator signal generated by the first oscillator. The second divider is coupled to the second oscillator, and is configured to divide a frequency of a second oscillator signal generated by the second oscillator. The frequency ratio circuit is coupled to the first divider and the second divider, and is configured to determine a frequency ratio of an output of the first divider to an output of the second divider. The temperature compensation circuit is coupled to the frequency ratio circuit and the first oscillator, and is configured to generate a compensated frequency based on the frequency ratio and the first oscillator signal.

A clock integrated circuit is provided. The clock integrated circuit includes: a first clock generator which includes a crystal oscillator configured to generate a first clock signal; and a second clock generator which includes a resistance-capacitance (RC) oscillator and a first frequency divider, and is configured to: generate a second clock signal using the first frequency divider based on a clock signal output from the RC oscillator; perform a first calibration operation for adjusting a frequency division ratio of the first frequency divider to a first frequency division ratio based on the first clock signal; and perform a second calibration operation for adjusting the first frequency division ratio to a second frequency division ratio based on a sensed temperature.

An integrated circuit apparatus includes an oscillation circuit that generates an oscillation signal by using a resonator, an output buffer circuit that outputs a clock signal based on the oscillation signal, a DC voltage generation circuit that generates a DC voltage used to generate the oscillation signal or the clock signal, a power source pad to which a power source voltage is supplied, a ground pad to which a ground voltage is supplied, and a clock pad via which the clock signal is outputted. The ground pad and the DC voltage generation circuit are disposed so as to overlap with each other in the plan view.

An oscillator includes: an outer package; an inner package accommodated in the outer package and fixed to the outer package via a heat insulating member; a vibration element accommodated in the inner package; a temperature sensor; a first circuit element accommodated in the inner package and including an oscillation circuit configured to oscillate the vibration element and generate a temperature-compensated oscillation signal based on the temperature sensor; and a second circuit element fixed to the outer package and including a frequency control circuit configured to control a frequency of the oscillation signal.

A method for multiphase frequency to voltage conversion includes generating for each cycle of an oscillating input, one of a plurality of non-overlapping clocks. A respective voltage in proportion to an input frequency of the oscillating input, is generated in response to each of the non-overlapping clocks, with a respective one of a plurality of frequency to voltage converters. Each of the respective voltages is summated to generate a voltage sum proportional to the input frequency.

A dual-output microelectromechanical system (MEMS) resonator can be operated selectively and concurrently in an in-plane mode of vibration and an out-of-plane mode of vibration to obtain, respectively, a first electrical signal having a first frequency and a second electrical signal having a second frequency that is less than the first frequency. The first and second electrical signals are mixed to obtain a third electrical signal having a third frequency, where the third frequency is proportional to a temperature of the MEMS resonator. The temperature is determined based on the third frequency. Values of the first and second frequencies can be adjusted based on the determined temperature to compensate for frequency deviations due to temperature deviations. Also described herein are methods and systems for determining the temperature of the dual-output MEMS and for performing frequency compensation, as well as a method of manufacturing the dual-output MEMS.