Seiko Epson Corporation

Hideo Haneda

Yasuhiro Sudo

Akio Tsutsumi

Katsuhiko Maki

Atsushi Tanaka

Takashi Kurashina

Yuichi Toriumi

Teppei Higuchi

Hisahiro Ito

Takemi Yonezawa

Tomoaki Takahashi

Shinichi Wakabayashi

Hideyuki Yamada

Tatsuya Takahashi

Provided is a physical quantity sensor attached to an electronic device provided with an actuator. The physical quantity sensor includes: a sensor element configured to output a detection signal corresponding to a physical quantity; and a circuit device configured to output an actuator drive signal for driving the actuator based on the detection signal. The circuit device has a resonance characteristic measurement mode of outputting the actuator drive signal for measuring a resonance characteristic of the electronic device by vibrating the electronic device, and a vibration-damping mode of outputting the actuator drive signal for reducing a vibration of the electronic device based on the resonance characteristic measured in the resonance characteristic measurement mode.

Physical quantity sensor and electronic device

The A/D converter includes a D/A conversion circuit configured to perform a D/A conversion on a DAC input digital value to output a DAC output signal, a difference output circuit for outputting difference signals based on a difference between the input signal and the DAC output signal, an A/D conversion circuit for performing an A/D conversion on the difference signals to output an ADC output digital value, and a control circuit for outputting the DAC input digital value based on the ADC output digital value. The control circuit outputs a first DAC input digital value and a second DAC input digital value different from the first DAC input digital value, and obtains ADC result data based on a first ADC output digital value obtained in accordance with the first DAC input digital value, a second ADC output digital value obtained in accordance with the second DAC input digital value, and the DAC input digital value.

A/D converter, digital-output temperature sensor, circuit device, and oscillator

The circuit device includes an integration period signal generation circuit, a polarity switching signal generation circuit, and first and second integration circuits. The integration period signal generation circuit generates a first integration period signal kept in an active state in the first integration period. The polarity switching signal generation circuit generates a first integration polarity switching signal making a transition at a timing synchronized with the reference clock signal in the first integration period, and a second integration polarity switching signal making a transition a predetermined clock count of the reference clock signal after the transition timing of the first integration polarity switching signal in the first integration period. The first integration circuit performs an integrating process in which an integration polarity is switched at the transition timing of the first integration polarity switching signal in the first integration period. The second integration circuit performs an integrating process in which an integration polarity is switched at the transition timing of the second integration polarity switching signal in the first integration period.

Circuit device, physical quantity measurement device, electronic apparatus, and vehicle

A circuit device includes an oscillation circuit that generates an oscillation signal using a resonator, a temperature detection circuit that outputs temperature detection data, a temperature compensation circuit, and a temperature detection rate control circuit. The temperature compensation circuit performs temperature compensation on an oscillation frequency of the oscillation signal based on the temperature detection data. The temperature detection rate control circuit controls a temperature detection rate at which the temperature detection circuit executes temperature detection. At this time, the temperature detection rate control circuit controls the temperature detection rate based on a variation in the temperature detection data.

Circuit device and oscillator

The digital-output temperature sensor includes a temperature sensor circuit, a current mirror circuit which makes a mirror current of a temperature detection current flow and pulls in a mirror current of a reference current to thereby output a first difference current from a first output node and output a second difference current from a second output node, a chopping circuit, and an A/D conversion circuit. The chopping circuit performs a chopping operation of making the mirror current of the reference current flow in a second state through a transistor of the current mirror circuit through which the mirror current of the temperature detection current flows in a first state, and making the mirror current of the temperature detection current flow in the second state through the transistor of the current mirror circuit through which the mirror current of the reference current flows in the first state.

Digital-output temperature sensor, circuit device, and oscillator

A circuit device includes an analog front-end circuit that receives a target signal is input, and a processing circuit that performs arithmetic processing based on an output signal from the analog front-end circuit. The analog front-end circuit includes a plurality of comparator circuits that compare the voltage level of the target signal to a plurality of threshold voltages and output a plurality of comparison result signals. The processing circuit obtains the transition timing of the target signal based on the comparison result signals and delayed-time information of the analog front-end circuit.

Circuit device, physical quantity measuring device, electronic apparatus, and vehicle

A circuit device includes an oscillation circuit and a processing circuit that generates capacitance control data. The oscillation circuit includes a variable capacitance circuit whose capacitance value is variably controlled based on the capacitance control data, and an oscillation frequency thereof is controlled based on the capacitance value of the variable capacitance circuit. The variable capacitance circuit includes a capacitor array. The capacitor array includes a plurality of capacitors each having a binary-weighted capacitance value, and a plurality of switches that are on-off controlled based on the capacitance control data. The processing circuit outputs the capacitance control data, which is subjected to dithering, so as to switch the capacitance value of the variable capacitance circuit between a first capacitance value and a second capacitance value in a time division manner.

A physical quantity detection circuit includes a passive filter that receives a first analog signal based on an output signal of a physical quantity detection element, an analog/digital conversion circuit, and a precharge circuit that includes an operational amplifier, a first chopper circuit provided between the passive filter and the operational amplifier, and a second chopper circuit provided between the operational amplifier and the input capacitance of the analog/digital conversion circuit and precharges an input capacitance of the analog/digital conversion circuit, the first and the second chopper circuits perform a chopping operation in synchronization with an operation that the analog/digital conversion circuit samples the second analog signal at the input capacitance, based on an output signal of the passive filter.

Physical quantity detection circuit, physical quantity sensor, electronic apparatus, vehicle, and operation method of physical quantity detection circuit

A real-time clock device includes a resonator, a clock signal generation circuit, a time-counting circuit, a terminal, and a time-to-digital conversion circuit. The clock signal generation circuit outputs a time-counting clock signal based on an oscillation clock signal. The time-counting circuit generates time-counting data based on the time-counting clock signal. An external signal is input to the terminal. The time-to-digital conversion circuit measures a time difference between a transition timing of a first signal based on the external signal and a transition timing of a second signal based on the oscillation clock signal or the time-counting clock signal with a resolution higher than a time-counting resolution of the time-counting circuit, and obtains time difference information corresponding to the time difference.

Real-time clock device and electronic apparatus

A circuit device includes an oscillation circuit that generates an oscillation signal by using a vibrator, a frequency adjustment circuit that adjusts an oscillation frequency of the oscillation circuit based on frequency adjustment data, a temperature sensor circuit that outputs temperature data, an arithmetic operation circuit, and a storage circuit. The arithmetic operation circuit outputs converted temperature data by performing, on the temperature data, conversion processing in which a slope of the converted temperature data with respect to the temperature data in a first temperature range is different from a slope of the converted temperature data with respect to the temperature data in a second temperature range. The storage circuit stores a lookup table representing a correspondence between the converted temperature data and the frequency adjustment data.

A frequency measurement circuit includes a first counter that counts a pulse number of a reference clock signal and generates first count data, a second counter that counts a pulse number of a measurement target clock signal and generates second count data, a time-to-digital conversion circuit that generates first time difference data indicating a time difference between a first timing at which the first counter starts counting of the pulse number and a second timing at which the second counter starts counting of the pulse number, and second time difference data indicating a time difference between a third timing at which the first counter ends counting of the pulse number and a fourth timing at which the second counter ends counting of the pulse number, and a calculation circuit that performs calculation based on the second count data, the first time difference data, and the second time difference data and generates frequency data indicating a frequency of the measurement target clock signal.

Frequency measurement circuit and frequency measurement apparatus

A circuit device is used in an electronic device including a receiver, a control circuit that performs processing on reception data received by the receiver using a clock signal, a transmitter that transmits transmission data generated by performing processing based on the reception data by the control circuit. The circuit device includes a time-to-digital conversion circuit that measures a time difference between a transition timing of a start signal based on the reception data and a transition timing of a stop signal based on the transmission data or the clock signal, and an output interface that outputs, to the control circuit, a measurement result of the time difference of the time-to-digital conversion circuit.

Circuit device, electronic device, communication system, and vehicle electronic key system

A circuit device includes a detection signal terminal to which a detection signal from a vibrator is input, a digital signal terminal that performs at least one of an input and an output of a digital signal, a detection circuit, and a signal generation circuit that generates a noise reduction signal based on the digital signal. The detection circuit includes an amplification circuit that amplifies the detection signal. The amplification circuit performs addition processing of a signal obtained by amplifying the detection signal and the noise reduction signal.

A circuit device includes a clock generation circuit, a signal generation circuit, a phase comparison circuit, and a processing circuit. The signal generation circuit generates a first signal making the transition at a transition timing of a first clock signal, a fine-judging signal making the transition at a transition timing of a second clock signal, a first coarse-judging signal making the transition at a transition timing of the second clock signal anterior to the fine-judging signal, and a second coarse-judging signal making the transition at a transition timing of the second clock signal posterior to the fine-judging signal. The phase comparison circuit performs the phase comparison between the second signal making the transition based on the first signal and each of the fine-judging signal, the first coarse-judging signal, and the second coarse-judging signal. The processing circuit sets the transition timing of the first signal and the transition timing of the fine-judging signal based on the phase comparison result, and converts a time difference between the first signal and the second signal into a digital value based on the setting result.

An oscillator includes a resonator, a clock signal generation circuit, a clock signal output terminal, an external signal input terminal, an interface circuit, and an interface terminal. The clock signal generation circuit oscillates the resonator to generate a clock signal. The clock signal output terminal outputs the clock signal. An external signal is input to the external signal input terminal. The interface circuit outputs time difference information obtained by measuring a time difference between a transition timing of a first signal based on the external signal input from the external signal input terminal and a transition timing of a second signal based on the clock signal, or frequency information obtained by measuring a frequency of a first clock signal, which is one of the clock signal and the external clock signal, based on a frequency of a second clock signal, which is the other of the clock signal and the external clock signal. The interface terminal is coupled to the interface circuit.

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Matsumoto, Japan

Hideo Haneda