Denso Corporation

Takanori Makino

Kazuyoshi Nagase

Yasuaki Makino

Seiki Aoyama

Katsunori Michiyama

Takamitsu Ookura

Noboru Endoh

Jyun Ishihara

An optical sensor includes: first and second light receiving elements on a semiconductor substrate; a light blocking film over the semiconductor substrate via a light transmitting film; and first and second openings corresponding to the light receiving elements and disposed in the light blocking film. First and second virtual lines are defined to extend from the centers of the first and second light receiving elements and pass through the centers of the first and second openings, respectively. At least one of elevation angles and left-right angles of the first and second virtual lines are different. The photosensitive area of the first light receiving element is larger than the aperture area of the first opening. The photosensitive area of the second light receiving element is larger than the aperture area of the second opening.

Optical sensor having a blocking film disposed over light receiving elements on a semiconductor substrate via a light transparent film for detecting an incident angle of light

An output circuit includes a constant current circuit that generates and supplies a constant current to an output terminal of the output circuit. Based on the constant current, the output circuit converts an input signal to an output signal having a voltage within a voltage range specified by upper and lower clamp voltages. The output signal is feedback to the constant current circuit. The constant current circuit changes the amount of the constant current in accordance with the output signal in such a manner that the constant current increases with an increase in the output signal and becomes zero when the output signal decreases to or below a threshold voltage. Thus, the upper clamp voltage is made as close to a power supply voltage as possible and the lower clamp voltage is made as close to a ground voltage as possible.

Output circuit and current source circuit used in the same

An analog switch used in a switched capacitor filter has N-channel and P-channel MOS FETs connected in parallel between input and output switch terminals, with capacitor charge currents being periodically produced from the output terminal. The filter derives an output signal with respect to a reference voltage and maintains the switch input and output terminal at the reference voltage, while respective substrate potentials of the N-channel and P-channel MOS FETs are fixed at the reference voltage, so that the analog switch does not produce an external flow of leakage current that can affect the output signal of the filter during each interval when the switch is open.

Analog switch having a minimized external flow of leakage current and switched capacitor filter incorporating the analog switch

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.

Switched-capacitor low-pass filter and semiconductor pressure sensor apparatus incorporating the filter

A temperature dependent sensitivity compensating circuit structure of a sensor is provided. The sensor includes a sensing element which has a TCS (Temperature Coefficient of Sensitivity). The circuit structure is designed to provide a temperature characteristic to current supplied to the sensing element, thereby compensating for a change in TCS of the sensing element.

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Oogaki, Japan

Takanori Makino