Abstract: A side collision detecting apparatus includes a pressure sensor disposed in a side door of a vehicle and including a diaphragm for detecting a pressure in the side door. The diaphragm has a pressure receiving surface configured to be distorted in accordance with a change in the pressure. The pressure sensor is arranged so as to satisfy one of a first condition where an angle between a line along which the pressure receiving surface extends and a horizontal line extending in a front-rear direction of the vehicle is from 60 degrees to 90 degrees and a second condition where the angle is less than 60 degrees or greater than 90 degrees and the pressure receiving surface is not vertical.

Abstract: A side collision detecting apparatus includes a pressure sensor disposed in a side door of a vehicle and including a diaphragm for detecting a pressure in the side door. The diaphragm has a pressure receiving surface configured to be distorted in accordance with a change in the pressure. The pressure sensor is arranged so as to satisfy one of a first condition where an angle between a line along which the pressure receiving surface extends and a horizontal line extending in a front-rear direction of the vehicle is from 60 degrees to 90 degrees and a second condition where the angle is less than 60 degrees or greater than 90 degrees and the pressure receiving surface is not vertical.

Abstract: A physical quantity sensor includes: a substrate; a movable element; two fixed elements; a carrier wave application element for applying two carrier waves to the fixed elements; a signal application element for applying a middle voltage to the movable element; and a detection circuit for detecting a physical quantity. The detection circuit executes a first self diagnosis process when the signal application element further applies a first self diagnosis signal to the movable element. The first self diagnosis signal has a first frequency for obtaining a resonant magnification equal to or larger than 1.1 times with respect to a resonant frequency of the movable element, so that the movable element is resonated and almost contacts or press contacts one fixed element. The detection circuit determines whether a sticking phenomenon occurs when the signal application element applies the first self diagnosis signal.

Abstract: A physical quantity sensor includes: a substrate; a movable element; two fixed elements; a carrier wave application element for applying two carrier waves to the fixed elements; a signal application element for applying a middle voltage to the movable element; and a detection circuit for detecting a physical quantity. The detection circuit executes a first self diagnosis process when the signal application element further applies a first self diagnosis signal to the movable element. The first self diagnosis signal has a first frequency for obtaining a resonant magnification equal to or larger than 1.1 times with respect to a resonant frequency of the movable element, so that the movable element is resonated and almost contacts or press contacts one fixed element. The detection circuit determines whether a sticking phenomenon occurs when the signal application element applies the first self diagnosis signal.

Abstract: An oscillator includes first, second and third inverters (1, 2, 3) connected in series. A feedback path is connected from the output terminal of the third inverter (3) to the input terminal of the first inverter 1 through a resistor (5) while a second feedback path is connected from the output terminal of the second inverter (2) to the input terminal of the first inverter (1) through a capacitor (4). The second feedback path further includes a resistor (6) having a temperature coefficient larger than that of resistor (5) is inserted to adjust the charge/discharge trigger voltage and charge/discharge time of the capacitor (4).

Abstract: A low-pass filter configured as a switched capacitor circuit in which capacitor charge switching is performed by 2-phase clock signals that control respective sets of switching elements, wherein an interval between a first-phase clock signal pulse and a succeeding second-phase clock signal pulse, during which no charging/discharging of capacitors should occur, is made as short as possible while ensuring that the two sets of switching elements cannot enter the ON state simultaneously. A low cut-off frequency can thereby be achieved, while using very small capacitor values.

Abstract: A sensor device includes a circuit chip and a sensor chip adhesively stacked on the circuit chip through a film type adhesive material. Stress moderation film for moderating stress applied to the circuit chip may be interposed between the circuit chip and the film type adhesive material.

Abstract: In a switched capacitor filter circuit, a switching transistor is connected to an operational amplifier for input of a switching control signal to the operational amplifier. A noise compensation transistor is provided between the switching transistor and the operational amplifier. The drain and the source of the noise compensation transistor are connected to each other. The noise compensation transistor is applied with an inverted signal of the switching signal, and generates feedthrough noise of the polarity inverted from that generated by the switching transistor in order to cancel the feedthrough noise.

Abstract: A low-pass filter configured as a switched capacitor circuit in which capacitor charge switching is performed by 2-phase clock signals that control respective sets of switching elements, wherein an interval between a first-phase clock signal pulse and a succeeding second-phase clock signal pulse, during which no charging/discharging of capacitors should occur, is made as short as possible while ensuring that the two sets of switching elements cannot enter the ON state simultaneously. A low cut-off frequency can thereby be achieved, while using very small capacitor values.

Abstract: An oscillator includes first, second and third inverters (1, 2, 3) connected in series. A feedback path is connected from the output terminal of the third inverter (3) to the input terminal of the first inverter 1 through a resistor (5) while a second feedback path is connected from the output terminal of the second inverter (2) to the input terminal of the first inverter (1) through a capacitor (4). The second feedback path further includes a resistor (6) having a temperature coefficient larger than that of resistor (5) is inserted to adjust the charge/discharge trigger voltage and charge/discharge time of the capacitor (4).

Abstract: In a switched capacitor filter circuit, a switching transistor is connected to an operational amplifier for input of a switching control signal to the operational amplifier. A noise compensation transistor is provided between the switching transistor and the operational amplifier. The drain and the source of the noise compensation transistor are connected to each other. The noise compensation transistor is applied with an inverted signal of the switching signal, and generates feedthrough noise of the polarity inverted from that generated by the switching transistor in order to cancel the feedthrough noise.

Abstract: A dynamic quantity sensor has a weigh portion that is supported by a base portion to be displaced by a dynamic quantity, a movable electrode protruding from the weigh portion, and a fixed electrode protruding from the base portion and defining a detection interval with the movable electrode. The detection interval changes in response to displacement of the weight portion for detecting the dynamic quantity. Each of the movable electrode and the fixed electrode has a tapered plane shape with a width that decreases from a root portion toward a tip portion thereof.

Abstract: The clock signal for the sample and hold circuit for sampling the C-V conversion circuit output generated by the control signal generation circuit is different in period from the clock signal for switched capacitor filter circuit for filtering the sample and hold circuit output such that the clock signal for the switched capacitor filter circuit is unchanged in period between the measuring and self-diagnostic modes.

Abstract: A semiconductor physical quantity sensor from which a stable sensor output can be obtained even when the usage environment changes. A silicon thin film is disposed on an insulating film on a supporting substrate, and a bridge structure having a weight part and moving electrodes and cantilever structures having fixed electrodes are formed as separate sections from this silicon thin film. The moving electrodes provided on the weight part and the cantilevered fixed electrodes are disposed facing each other. Slits are formed at root portions of the cantilevered fixed electrodes at the fixed ends thereof, and the width W1 of the root portions is thereby made narrower than the width W2 of the fixed electrodes proper. As a result, the transmission of warp of the supporting substrate to the cantilevered fixed electrodes is suppressed.

Abstract: A semiconductor dynamic quantity sensor includes a semiconductor support substrate having a specific resistance equal to or less than 3&OHgr; cm. An insulation film is provided on the support substrate and a semiconductor layer is provided on the support substrate with the insulation film interposed therebetween. The semiconductor layer has a specific resistance equal to or less than 3&OHgr; cm. A movable electrode is provided in the semiconductor layer to be displaced according to a dynamic quantity acting thereto. A fixed electrode is fixedly provided in the semiconductor layer to make a specific gap with the movable electrode and to from a capacitor with the movable electrode. The capacitor has a capacity that changes in response to displacement of the movable electrode to detect the dynamic quantity.

Abstract: The clock signal for the sample and hold circuit for sampling the C-V conversion circuit output generated by the control signal generation circuit is different in period from the clock signal for switched capacitor filter circuit for filtering the sample and hold circuit output such that the clock signal for the switched capacitor filter circuit is unchanged in period between the measuring and self-diagnostic modes.

Abstract: A dynamic quantity sensor has a weigh portion that is supported by a base portion to be displaced by a dynamic quantity, a movable electrode protruding from the weigh portion, and a fixed electrode protruding from the base portion and defining a detection interval with the movable electrode. The detection interval changes in response to displacement of the weight portion for detecting the dynamic quantity. Each of the movable electrode and the fixed electrode has a tapered plane shape with a width that decreases from a root portion toward a tip portion thereof.

Abstract: In a method for manufacturing a semiconductor acceleration sensor, a movable portion including a mass portion and movable electrodes is formed in a single crystal silicon thin film provided on a silicon wafer through an insulation film by etching both the single crystal silicon thin film and the silicon wafer. In this case, the movable portion is finally defined at a movable portion defining step that is carried out in a vapor phase atmosphere. Accordingly, the movable portion is prevented from sticking to other regions due to etchant during the manufacture thereof.

Abstract: In a method for manufacturing a semiconductor acceleration sensor, a movable portion including a mass portion and movable electrodes is formed in a single crystal silicon thin film provided on a silicon wafer through an insulation film by etching both the single crystal silicon thin film and the silicon wafer. In this case, the movable portion is finally defined at a movable portion defining step that is carried out in a vapor phase atmosphere. Accordingly, the movable portion is prevented from sticking to other regions due to etchant during the manufacture thereof.

Abstract: Magnetic resistive elements 4 and 5 cooperatively detect the change of the magnetic field responsive to the rotation of a gear 2 fixed to a shaft 1. An amplification circuit 6 comprises an operational amplifier 7 having an input terminal to which a gain-determining input resistor 8 is connected. A gain-determining feedback resistor 9 is provided in a feedback path of the operational amplifier 7. The gain-determining resistors 8 and 9 are formed by a P well region and a P+ region of a MOS process element. The temperature characteristics of the gain-determining resistor 8 and 9 are opposed to that of the magnetic resistive elements 4 and 5. The temperature characteristics of the gain of the operational amplifier 7 cancel the temperature characteristics of the magnetic resistive elements 4 and 5.