An integrated circuit device includes a first pad and a second pad electrically coupled to one end and the other end of a resonator, an oscillation circuit that is electrically coupled to the first pad and the second pad and generates an oscillation signal by causing the resonator to oscillate, and an output circuit that outputs a clock signal based on the oscillation signal. The oscillation circuit is disposed along a first side of the integrated circuit device among the first side, a second side that intersects the first side, a third side that is an opposite side of the first side, and a fourth side that is an opposite side of the second side. The first pad and the second pad are disposed in the oscillation circuit along the first side in a plan view, and the output circuit is disposed along the second side.

An integrated circuit includes an inverter, first and second capacitors, a resistor, and a transistor. The inverter has an input and an output. The first capacitor is coupled to a ground. The transistor has a first transistor terminal, a second transistor terminal, and a control input. The first transistor terminal is coupled to the first capacitor and the second transistor terminal is coupled to the input of the inverter. The second capacitor is coupled between the output of the inverter and the ground. The resistor is coupled between the output of the inverter and the first transistor terminal.

An integrated circuit device includes an oscillation circuit that generates an oscillation signal by causing a resonator to oscillate, a temperature compensation circuit that performs temperature compensation of an oscillation frequency of the oscillation circuit, an output circuit that outputs a clock signal based on the oscillation signal, a first regulator that generates a first regulated power supply voltage based on a power supply voltage and supplies the first regulated power supply voltage to the temperature compensation circuit, and a second regulator that generates a second regulated power supply voltage based on the power supply voltage and supplies the second regulated power supply voltage to the output circuit.

An oscillator includes a resonator and an integrated circuit, the integrated circuit includes an oscillation circuit that oscillates the resonator, a temperature sensor, a temperature compensation circuit that compensates for temperature characteristics of the resonator based on an output signal of the temperature sensor, an output circuit that receives a signal output from the oscillation circuit and outputs an oscillation signal, and a heat generating circuit, and in the heat generating circuit, a current flows in a first period after supply of a power supply voltage from the outside is started to generate heat and no current flows in the second period after the first period ends.

A vibration device includes a semiconductor substrate having a first surface and a second surface in an obverse-reverse relationship, a vibration element disposed on the first surface, a lid bonded to the first surface, an integrated circuit disposed on the first surface, a terminal disposed on the second surface, a through electrode which penetrates the semiconductor substrate, and is configured to electrically couple the terminal and the integrated circuit to each other, and a first capacitor which is provided with a first recess provided to the semiconductor substrate and opening in the first surface, an insulating film disposed on an inside surface of the first recess, and an electrically-conductive material filling the first recess, and has a first capacitance between the electrically-conductive material and the semiconductor substrate, wherein the electrically-conductive material does not have contact with the terminal at the second surface side.

Provided is a circuit device including: a first terminal electrically coupled to one end of a vibrator; a second terminal electrically coupled to the other end of the vibrator; an oscillation circuit electrically coupled to the first terminal and the second terminal, and oscillating the vibrator; a third terminal to which an external input signal is input; a switch circuit provided between a first wiring which couples the first terminal and the oscillation circuit with each other and the third terminal, and having a P-type transistor; and a control circuit outputting a regulated voltage, in which a power supply voltage is regulated, as a substrate voltage of the P-type transistor.

Provided is a circuit device including: an oscillation circuit oscillating a vibrator, in which the oscillation circuit includes a variable capacitance circuit having a first variable capacitance element and a second variable capacitance element constituted by a first transistor and a second transistor, and a reference voltage supply circuit. The first reference voltage is supplied to a first gate of the first transistor and a capacitance control voltage is supplied to a first impurity region of the first transistor, the second reference voltage is supplied to a second gate of the second transistor and the capacitance control voltage is supplied to a second impurity region of the second transistor, and the capacitance control voltage is supplied to a first common impurity region of the first transistor and the second transistor.

A crystal oscillator circuit comprises: a crystal oscillator; and an injection frequency generating circuit, the injection frequency generating circuit being configured to sense a signal of the crystal oscillator and amplify the sensed signal, the injection frequency generating circuit being further configured to inject the amplified signal to the crystal oscillator; wherein the crystal oscillator circuit is configured such that the crystal oscillator receives the amplified signal during an initial start-up period of the crystal oscillator and stops receiving the amplified signal at an end of the initial start-up period.

A semiconductor device and a method for controlling amplitude of signal in the semiconductor device are provided. The semiconductor device comprises a signal generator configured to output a sinewave, a comparator configured to compare a magnitude of the sinewave with a magnitude of a reference signal at a first timing corresponding to a timing control signal and to output a comparison result, and a control signal adjustor configured to adjust one of the current control signal and a timing control signal depending on the comparison result of the comparator.

A method for startup of a crystal oscillator (XO) with aid of external clock injection, associated XO and a monitoring circuit therein are provided. The XO includes an XO core circuit, an external oscillator, and an injection switch, where a quality factor of the external oscillator is lower than a quality factor of the XO core circuit. The method includes: utilizing the external oscillator to generate an injected signal; turning on the injection switch to make energy of the injected signal be injected into the XO core circuit, where an amplitude modulation (AM) signal is generated according to combination of the injected signal and an intrinsic oscillation signal from the XO core circuit; and controlling the external oscillator to selectively change an injection frequency of the injected signal according to the AM signal. More particularly, the injection switch is not turned off until the startup process is completed.