Abstract: A current sensor includes: a bus bar defining a longitudinal direction along one direction and in which an alternating current flows along the longitudinal direction; a sensor unit that outputs a detection signal based on a magnetic field generated according to the alternating current flowing through the bus bar; and a sensor housing in which the bus bar and the sensor unit are arranged. The bus bar is configured by a first bus bar and a second bus bar stacked in an arrangement direction of the bus bar and the sensor unit. The bus bar includes a covered portion covered with the sensor housing and a fastening portion exposed from the sensor housing. The first bus bar and the second bus bar are arranged in a state in which a gap is defined between the first bus bar and the second bus bar in the covered portion.

Abstract: A signal processing device includes a signal processor, a plurality of communicators, and a switch controller. The signal processor performs a preset signal processing for a detection signal that is output from a sensor. The plurality of communicators output communication data from an output terminal after converting data from the signal processor to communication data for different communication methods. The switch controller controls the data output operation of each of the plurality of communicators and then performs a switch operation to validate the data output operation of one of the plurality of communicators based on a selection signal that selects one of the communication methods. The switch controller sets the plurality of communicators to a high impedance output state at least at a time of performing the switch operation.

Abstract: A signal processing device includes a signal processor, a plurality of communicators, and a switch controller. The signal processor performs a preset signal processing for a detection signal that is output from a sensor. The plurality of communicators output communication data from an output terminal after converting data from the signal processor to communication data for different communication methods. The switch controller controls the data output operation of each of the plurality of communicators and then performs a switch operation to validate the data output operation of one of the plurality of communicators based on a selection signal that selects one of the communication methods. The switch controller sets the plurality of communicators to a high impedance output state at least at a time of performing the switch operation.

Abstract: A circuit chip is connected to a sensor chip in a sub-unit via a communication terminal, and includes an output wave formation circuit that performs communication by controlling a voltage of a power supply supplied from an electronic control unit (ECU) to raise a voltage level of an output signal. When the voltage of the power supply monitored by a voltage monitor rises above a threshold value, a control circuit lowers a voltage of a signal from the output wave formation circuit, thereby preventing an excessive rise of the power supply voltage used in a signal communication.

Abstract: A signal processing device includes: a signal processing circuit that processes an input signal, and outputs a signal corresponding to the input signal; an offset input device that inputs a diagnosis offset signal as an internal signal in a passage between an input side and an output side of the signal processing circuit; a self-diagnosis device that performs a self-diagnosis of the signal processing circuit based on a variation in the signal output from the signal processing circuit when the diagnosis offset signal input by the offset input device is varied by a predetermined amount; and an extraction device that removes a component of the diagnosis offset signal from the signal output from the signal processing circuit, and extracts only a signal corresponding to the input signal.

Abstract: A capacitive physical quantity detector includes: a capacitor having an electrostatic capacitance changeable with physical quantity; a converter converting a capacitance change to a voltage; and a selector having a comparator and a switching element. The converter includes a C-V converting circuit having an operational amplifier for amplifying a first signal from the capacitor, a main switch between input and output terminals of the operational amplifier, feedback capacitors and feedback switches. Each feedback switch connects a feedback capacitor to the main switch when the feedback switch is closed. The selector closes the feedback switches based on a second signal of the converter. The comparator compares the second signal with a threshold voltage. The switching element switches the feedback switches according to a third signal from the comparator to set the second signal smaller than a saturated voltage and larger than the threshold voltage.

Abstract: A capacitive physical quantity detector includes: a capacitor having an electrostatic capacitance changeable with physical quantity; a converter converting a capacitance change to a voltage; and a selector having a comparator and a switching element. The converter includes a C-V converting circuit having an operational amplifier for amplifying a first signal from the capacitor, a main switch between input and output terminals of the operational amplifier, feedback capacitors and feedback switches. Each feedback switch connects a feedback capacitor to the main switch when the feedback switch is closed. The selector closes the feedback switches based on a second signal of the converter. The comparator compares the second signal with a threshold voltage. The switching element switches the feedback switches according to a third signal from the comparator to set the second signal smaller than a saturated voltage and larger than the threshold voltage.