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.

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.

A circuit device includes a control voltage input terminal to which a control voltage is inputted, an A/D conversion circuit A/D-converting the control voltage to generate control voltage data and A/D-converting a temperature detection voltage from a temperature sensor to generate temperature detection data, a processing circuit generating temperature compensation data of an oscillation frequency based on the temperature detection data and performing addition processing of the temperature compensation data and the control voltage data to generate frequency control data of the oscillation frequency, and an oscillation signal generation circuit generating an oscillation signal of the oscillation frequency set by the frequency control data, using the frequency control data and a resonator.

A circuit device includes a processing circuit and an oscillation signal generation circuit. The processing circuit performs Kalman filter processing for a result of phase comparison between an input signal based on an oscillation signal and a reference signal and performs loop filter processing for the result of phase comparison. The oscillation signal generation circuit generates the oscillation signal of an oscillation frequency set by frequency control data which is output data of the loop filter processing by using the frequency control data and a resonator. The processing circuit estimates a truth value for an observed value of the result of phase comparison by using the Kalman filter processing.

A clock oscillator includes with a pullable BAW oscillator to generate an output signal with a target frequency. The BAW oscillator is based on a BAW resonator and voltage-controlled variable load capacitance, responsive to a capacitance control signal to provide a selectable load capacitance. An oscillator driver (such as a differential negative gm transconductance amplifier), is coupled to the BAW oscillator to provide an oscillation drive signal. The BAW oscillator is responsive to the oscillation drive signal to generate the output signal with a frequency based on the selectable load capacitance. The oscillator driver can include a bandpass filter network with a resonance frequency substantially at the target frequency.

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.

An oscillation circuit includes a first node, a first switching element, and a second switching element and has a first mode in which the first switching element does not electrically couple the first external connection terminal and the first node and the second switching element does not electrically couple the first node and the second external connection terminal which is electrically coupled to one end of a resonator and a second mode in which the first switching element electrically couples the first external connection terminal and the first node and the second switching element electrically couples the first node and the second external connection terminal, and in the first mode, a voltage of the first node is fixed.

A digital phase-locked loop (DPLL) includes a time-to-digital converter (TDC) having a first clock input, a second clock input, and a TDC output. The DPLL includes a digital loop filter (DLF). The DLF output controls a numerically-controlled bulk acoustic wave oscillator (NCBO). The NCBO output is divided down a fractional-N divider and is fed back to the TDC. The NCBO includes a reference oscillator, a phase and/or frequency detector, a charge pump, a loop filter, a voltage-controlled bulk acoustic wave oscillator (VCBO) and a feedback fractional-N divider that has a numerical control input, which is controlled by DLF output of DPLL. The NCBO forms a stable feedback loop and have a loop bandwidth much wider than DPLL loop bandwidth. In steady state, the NCBO output frequency can be linearly numerically adjusted. An auxiliary PLL or a fractional output divider can be used to generate additional needed frequencies.

A circuit device includes a first pad and a second pad that are disposed in a first pad disposition region along a first side; a third pad and a fourth pad that are disposed in a second pad disposition region along a second side which faces the first side; and a first to fourth electrostatic protection circuits that are disposed in a circuit disposition region between the first pad disposition region and the second pad disposition region and are connected to the first to fourth pads.

A resonator device includes first and second resonators and an integrated circuit device. The integrated circuit device includes a first oscillation circuit configured to oscillate the first resonator, a second oscillation circuit configured to oscillate the second resonator, and a processing circuit configured to perform processing by using frequency difference information or frequency comparison information between a first clock signal generated by oscillating the first resonator and a second clock signal generated by oscillating the second resonator. The first resonator is supported on the integrated circuit device by a first support portion. The second resonator is supported on the integrated circuit device by a second support portion.