Abstract: A capacitive sensor device includes first and second sensor capacitors coupled in series, a clock signal generating part, an operational amplifier, a feedback capacitor, a compensating capacitor, and a compensating signal generating part. The clock signal generating part generates a first clock signal and the second clock signal applied to the first and second sensor capacitors, respectively. The compensating signal generating part generates a compensating signal applied to the compensating capacitor. The first clock signal and the second clock signal have the same frequency and the same amplitude and have phases being opposite each other. The compensating signal has a frequency same as the first clock signal and the second clock signal, has a phase same as one of the first clock signal and the second clock signal, and has an amplitude that is adjustable.

Abstract: A peak voltage detector circuit detects a peak voltage of an input voltage. The input voltage is input into a first input terminal of a comparator. A counter circuit counts up a counter value in synchronization with a first clock signal, when a signal output from the comparator is in a first state. The counter circuit counts down the counter value in synchronization with a second clock signal. A digital-analog conversion circuit outputs an output voltage corresponding to the counter value, and the output voltage is input into a second input terminal of the comparator. The first clock signal has a wave period shorter than that of the second clock signal.

Abstract: A capacitive sensor device includes first and second sensor capacitors coupled in series, a clock signal generating part, an operational amplifier, a feedback capacitor, a compensating capacitor, and a compensating signal generating part. The clock signal generating part generates a first clock signal and the second clock signal applied to the first and second sensor capacitors, respectively. The compensating signal generating part generates a compensating signal applied to the compensating capacitor. The first clock signal and the second clock signal have the same frequency and the same amplitude and have phases being opposite each other. The compensating signal has a frequency same as the first clock signal and the second clock signal, has a phase same as one of the first clock signal and the second clock signal, and has an amplitude that is adjustable.

Abstract: A magnetic sensor apparatus includes a semiconductor substrate and a magnetic impedance device for detecting a magnetic field. The magnetic impedance device is disposed on the substrate. The magnetic sensor apparatus has minimum size and is made with low manufacturing cost. Here, the magnetic impedance device detects a magnetic field in such a manner that impedance of the device is changed in accordance with the magnetic filed when an alternating current is applied to the device and the impedance is measured by an external electric circuit.

Abstract: 1st to nth pairs of transistors (n=an odd number) are connected in parallel, and each pair of transistors has an upper transistor and a lower transistor connected in series. A point between the upper transistor and the lower transistor of a preceding pair of transistors is connected to a gate of the lower transistor of a subsequent transistor, and the point between the upper transistor and the lower transistor of nth pair of transistors is connected to the gate of the first lower transistor. A capacitor is inserted between the lower transistor and a direct power source. A current regulating circuit connected to gates of the upper transistors, wherein the current regulating circuit supplies a gate voltage to each gate of the each upper transistor.

Abstract: The present invention reliably removes a signal change associated with a noise component from a comparison signal of a comparator. A comparator circuit includes a comparator and a timer circuit. After a reversal of the comparison signal, if the level of the comparator is sustained at least from a first time to a second time, an output signal is reversed and output. The timer circuit includes a memory unit that is shifted to a memory state in which the reversal of the comparison signal is stored at the first time if the reversal is verified. If the comparison signal is reversed during the interval between the first time and second time, the memory state is cleared.

Abstract: A peak voltage detector circuit detects a peak voltage of an input voltage. The input voltage is input into a first input terminal of a comparator. A counter circuit counts up a counter value in synchronization with a first clock signal, when a signal output from the comparator is in a first state. The counter circuit counts down the counter value in synchronization with a second clock signal. A digital-analog conversion circuit outputs an output voltage corresponding to the counter value, and the output voltage is input into a second input terminal of the comparator. The first clock signal has a wave period shorter than that of the second clock signal.

Abstract: A magnetic sensor apparatus includes a semiconductor substrate and a magnetic impedance device for detecting a magnetic field. The magnetic impedance device is disposed on the substrate. The magnetic sensor apparatus has minimum size and is made with low manufacturing cost. Here, the magnetic impedance device detects a magnetic field in such a manner that impedance of the device is changed in accordance with the magnetic filed when an alternating current is applied to the device and the impedance is measured by an external electric circuit.

Abstract: A magnetic sensor apparatus includes a semiconductor substrate and a magnetic impedance device for detecting a magnetic field. The magnetic impedance device is disposed on the substrate. The magnetic sensor apparatus has minimum size and is made with low manufacturing cost. Here, the magnetic impedance device detects a magnetic field in such a manner that impedance of the device is changed in accordance with the magnetic filed when an alternating current is applied to the device and the impedance is measured by an external electric circuit.

Abstract: A peak voltage detector circuit detects a peak voltage of an input voltage. The input voltage is input into a first input terminal of a comparator. A counter circuit counts up a counter value in synchronization with a first clock signal, when a signal output from the comparator is in a first state. The counter circuit counts down the counter value in synchronization with a second clock signal. A digital-analog conversion circuit outputs an output voltage corresponding to the counter value, and the output voltage is input into a second input terminal of the comparator. The first clock signal has a wave period shorter than that of the second clock signal.

Abstract: A binarization circuit for binarizing a pulsative analog signal includes: a first comparator circuit for reversing an output signal when the analog signal becomes smaller than a threshold voltage and when the analog signal becomes larger than a high side threshold voltage; a second comparator circuit for reversing an output signal when the analog signal becomes larger than the threshold voltage and when the analog signal becomes smaller than a low side threshold voltage; and a selector circuit for inputting the output signals from the first and second comparator circuits and for reversing an output signal when the analog signal becomes smaller than the threshold voltage and when the analog signal becomes larger than the threshold voltage.

Abstract: 1st to nth pairs of transistors (n=an odd number) are connected in parallel, and each pair of transistors has an upper transistor and a lower transistor connected in series. A point between the upper transistor and the lower transistor of a preceding pair of transistors is connected to a gate of the lower transistor of a subsequent transistor, and the point between the upper transistor and the lower transistor of nth pair of transistors is connected to the gate of the first lower transistor. A capacitor is inserted between the lower transistor and a direct power source. A current regulating circuit connected to gates of the upper transistors, wherein the current regulating circuit supplies a gate voltage to each gate of the each upper transistor.

Abstract: A reference voltage circuit includes an operational amplifier, a first fixed resistance resistor, a second fixed resistance resistor, a third fixed resistance resistor, a first diode and a second diode. The reference voltage circuit further includes a fourth fixed resistance resistor having an end connected to a non-inverting input terminal of the operational amplifier and the other end connected to the first diode. The reference voltage circuit is characterized by a value of the resistance of the fourth resistor being less than the resistance of the first resistor and a temperature coefficient of the fourth resistor being greater than any of the temperature coefficients of the first, second and third resistors.

Abstract: A magnetic sensor apparatus includes a semiconductor substrate and a magnetic impedance device for detecting a magnetic field. The magnetic impedance device is disposed on the substrate. The magnetic sensor apparatus has minimum size and is made with low manufacturing cost. Here, the magnetic impedance device detects a magnetic field in such a manner that impedance of the device is changed in accordance with the magnetic filed when an alternating current is applied to the device and the impedance is measured by an external electric circuit.

Abstract: A reference voltage circuit includes an operational amplifier, a first fixed resistance resistor, a second fixed resistance resistor, a third fixed resistance resistor, a first diode and a second diode. The reference voltage circuit further includes a fourth fixed resistance resistor having an end connected to a non-inverting input terminal of the operational amplifier and the other end connected to the first diode. The reference voltage circuit is characterized by a value of the resistance of the fourth resistor being less than the resistance of the first resistor and a temperature coefficient of the fourth resistor being greater than any of the temperature coefficients of the first, second and third resistors.

Abstract: First and second predetermined charging voltages are applied between the movable and fixed electrodes of a capacitive type of sensor to measure first and second capacitances between the movable and fixed electrodes, respectively. The first and second electrostatic capacitances are compared to obtain a characteristic of the sensor from a result of comparison. In measuring the first and second capacitances, first and second charging voltages are generated of which magnitudes are determined in accordance with the first and second capacitances, respectively. Equalization is made between the first output voltage when the first charging voltage is applied between the movable and fixed electrodes in a predetermined normal condition of the movable electrode and the second output voltage outputted when the second charging voltage is applied between the movable and fixed electrodes in the predetermined normal condition.

Abstract: A magnetic sensor apparatus includes a semiconductor substrate and a magnetic impedance device for detecting a magnetic field. The magnetic impedance device is disposed on the substrate. The magnetic sensor apparatus has minimum size and is made with low manufacturing cost. Here, the magnetic impedance device detects a magnetic field in such a manner that impedance of the device is changed in accordance with the magnetic filed when an alternating current is applied to the device and the impedance is measured by an external electric circuit.

Abstract: In a capacitive sensor apparatus, a capacitive sensor includes a plurality of physical-quantity-detection capacitors each having a movable electrode and a fixed electrode. A conversion device operates for converting an output signal of the capacitive sensor into an apparatus output signal. Each of the physical-quantity-detection capacitors is selectively connected and disconnected to and from the conversion device. A determination is made as to whether or not each of the physical-quantity-detection capacitors fails in response to the sensor output signal. When it is determined that a first one of the physical-quantity-detection capacitors fails, the first one is disconnected from the conversion device and a second one of the physical-quantity-detection capacitors is connected to the conversion device.

Abstract: A capacitive physical load sensor includes a substrate, which has fixed electrodes, and a diaphragm, which has movable electrodes. The diaphragm is located across a gap from the substrate, and retaining parts for the diaphragm are formed around the diaphragm. Protruding parts extend into the gap from the diaphragm or from the substrate. The protruding parts support the diaphragm at different levels of deformation to alter the characteristics of the diaphragm and extend its range.

Abstract: First and second predetermined charging voltages are applied between the movable and fixed electrodes of a capacitive type of sensor to measure first and second capacitances between the movable and fixed electrodes, respectively. The first and second electrostatic capacitances are compared to obtain a characteristic of the sensor from a result of comparison. In measuring the first and second capacitances, first and second charging voltages are generated of which magnitudes are determined in accordance with the first and second capacitances, respectively. Equalization is made between the first output voltage when the first charging voltage is applied between the movable and fixed electrodes in a predetermined normal condition of the movable electrode and the second output voltage outputted when the second charging voltage is applied between the movable and fixed electrodes in the predetermined normal condition.