Abstract: A DC-DC converter that converts a DC input voltage supplied from a DC power supply and that outputs a DC voltage with a different potential is shown. The DC-DC converter includes the following. A control circuit controls a switching element in accordance with a potential difference between a feedback voltage proportional to an output voltage and a predetermined reference voltage. A current supply circuit that causes a predetermined current to flow. A voltage correction circuit that corrects the reference voltage or the feedback voltage. The voltage correction circuit is configured to determine a voltage correction amount, based on information about a resistance on a load side input from outside when a current of the current supply circuit is output, and correct the reference voltage or the feedback voltage.

Abstract: An optical module includes a fixed substrate, and a sensor substrate secured to the fixed substrate and having a through-hole formed therein. A light emitting device is secured to the fixed substrate at a position in the through-hole. A light receiving device is provided in the sensor substrate. A dummy light receiving device is formed between the light receiving device and the through-hole, around the through-hole, and in the sensor substrate. The light receiving device and the dummy light receiving device are made of an impurity diffusion layer having a same conductive type as a conductive type of a surface layer of the sensor substrate. The dummy light receiving device is deeper than the light receiving device.

Abstract: An optical module includes a fixed substrate, and a sensor substrate secured to the fixed substrate and having a through-hole formed therein. A light emitting device is secured to the fixed substrate at a position in the through-hole. A light receiving device is provided in the sensor substrate. A dummy light receiving device is formed between the light receiving device and the through-hole, around the through-hole, and in the sensor substrate. The light receiving device and the dummy light receiving device are made of an impurity diffusion layer having a same conductive type as a conductive type of a surface layer of the sensor substrate. The dummy light receiving device is deeper than the light receiving device.

Abstract: A sensor device is provided including: an electric wire; a semiconductor device including an inductor and an amplifier, the inductor being configured to detect a magnetic field generated around the electric wire, the amplifier including a bipolar element configured to amplify a voltage generated at the inductor; and a substrate on which the first semiconductor device and the electric wire are arranged such that the first semiconductor device is apart from the electric wire by at least a given distance. In a plan view of the substrate, the electric wire does not overlap the first semiconductor device.

Abstract: A sensor device is provided including: an electric wire; a semiconductor device including an inductor and an amplifier, the inductor being configured to detect a magnetic field generated around the electric wire, the amplifier including a bipolar element configured to amplify a voltage generated at the inductor; and a substrate on which the first semiconductor device and the electric wire are arranged such that the first semiconductor device is apart from the electric wire by at least a given distance. In a plan view of the substrate, the electric wire does not overlap the first semiconductor device.

Abstract: A motor driver apparatus that is formed of a semiconductor integrated circuit which is supplied with an electric power and drives a direct current motor includes a signal generating part that generates an indication signal for indicating a back electromotive force generation period while the direct current motor generates a back electromotive force, a removing part that detects a voltage variation generated in a power-supply voltage by the back electromotive force generated by the direct-current motor during the back electromotive force generation period indicated by the indication signal, and removes the detected voltage variation, and a limiting part that limits the power-supply voltage so as to be less than a predetermined voltage at a speed higher than that in the removing part.

Abstract: Disclosed is a current and voltage detection circuit comprising: a voltage input terminal to which a direct current voltage is applied; a voltage comparison circuit that determines which of the applied voltage and a predetermined voltage is larger; a switching element connected in series to a current-voltage conversion unit, between a positive electrode terminal of the power supply and a reference potential point of the circuit; and a control circuit that generates a control signal of the switching element in response to output of the voltage comparison circuit, wherein the circuit turns ON the switching element and determines the voltage, by the voltage comparison circuit, when a voltage supply capability or current supply capability is low; and turns OFF the switching element by the control signal and determines the voltage, when the voltage comparison circuit determines that the voltage is higher than the predetermined voltage.

Abstract: A motor driver apparatus that is formed of a semiconductor integrated circuit which is supplied with an electric power and drives a direct current motor includes a signal generating part that generates an indication signal for indicating a back electromotive force generation period while the direct current motor generates a back electromotive force, a removing part that detects a voltage variation generated in a power-supply voltage by the back electromotive force generated by the direct-current motor during the back electromotive force generation period indicated by the indication signal, and removes the detected voltage variation, and a limiting part that limits the power-supply voltage so as to be less than a predetermined voltage at a speed higher than that in the removing part.

Abstract: A semiconductor integrated circuit includes an output MOS transistor and a back gate control circuit. The output MOS transistor includes a first electrode connected to a power supply terminal and a second electrode connected to an output terminal. The output MOS transistor is configured to turn on and off to cause communications to be performed with another semiconductor integrated circuit connected to the output terminal. The back gate control circuit is configured to control an electric potential at a back gate of the output MOS transistor so that a current path between the power supply terminal and the output terminal at a time when a power supply connected to the power supply terminal is turned off is interrupted.

Abstract: A plurality of current control MOS transistors and a plurality of current detection systems are provided, each of the current detection systems including a current detection transistor current-mirror connected to the current control MOS transistor and a current-voltage converter connected in series to the current detection transistor. The current detection systems are switched between one another for operation in response to the intensity of a charging current flowing through the current control transistors.

Abstract: An output current detecting circuit includes: a current detecting transistor having a size smaller than that of an output transistor and a control terminal, to which a voltage same as a control voltage of the output transistor is applied; a sensing resistor connected to the current detecting transistor in a serial mode; a comparison circuit comparing a voltage converted by the sensing resistor and a reference voltage to judge a magnitude of a current flowing through the output transistor; and a reference voltage generating circuit, wherein the reference voltage generating circuit includes a constant current circuit flowing a constant current and a resistance element having one terminal connected to a power source voltage terminal, the reference voltage generating circuit generating the reference voltage based on a power source voltage by the conversion of the constant current into a voltage by flowing the constant current through the resistance element.

Abstract: Disclosed is a reference voltage generating circuit including a constant current circuit which comprises: a first resistive element and a bipolar transistor connected in series between a supply voltage terminal and a constant potential point; a first MOS transistor having a gate connected to a node connecting the first resistive element with the bipolar transistor; a second resistive element connected in series between a source of the first MOS transistor and the constant potential point; a second MOS transistor connected between a drain of the first MOS transistor and the supply voltage terminal; and a third MOS transistor forming a current mirror in conjunction with the second MOS transistor, wherein a constant current generated by the constant current circuit or a current proportional to the generated constant current is converted to a voltage as a reference voltage.

Abstract: A plurality of current control MOS transistors and a plurality of current detection systems are provided, each of the current detection systems including a current detection transistor current-mirror connected to the current control MOS transistor and a current-voltage converter connected in series to the current detection transistor. The current detection systems are switched between one another for operation in response to the intensity of a charging current flowing through the current control transistors.

Abstract: Disclosed is a current and voltage detection circuit comprising: a voltage input terminal to which a direct current voltage is applied; a voltage comparison circuit that determines which of the applied voltage and a predetermined voltage is larger; a switching element connected in series to a current-voltage conversion unit, between a positive electrode terminal of the power supply and a reference potential point of the circuit; and a control circuit that generates a control signal of the switching element in response to output of the voltage comparison circuit, wherein the circuit turns ON the switching element and determines the voltage, by the voltage comparison circuit, when a voltage supply capability or current supply capability is low; and turns OFF the switching element by the control signal and determines the voltage, when the voltage comparison circuit determines that the voltage is higher than the predetermined voltage.

Abstract: Disclosed is a reference voltage generating circuit including a constant current circuit which comprises: a first resistive element and a bipolar transistor connected in series between a supply voltage terminal and a constant potential point; a first MOS transistor having a gate connected to a node connecting the first resistive element with the bipolar transistor; a second resistive element connected in series between a source of the first MOS transistor and the constant potential point; a second MOS transistor connected between a drain of the first MOS transistor and the supply voltage terminal; and a third MOS transistor forming a current mirror in conjunction with the second MOS transistor, wherein a constant current generated by the constant current circuit or a current proportional to the generated constant current is converted to a voltage as a reference voltage.

Abstract: An output current detecting circuit includes: a current detecting transistor having a size smaller than that of an output transistor and a control terminal, to which a voltage same as a control voltage of the output transistor is applied; a sensing resistor connected to the current detecting transistor in a serial mode; a comparison circuit comparing a voltage converted by the sensing resistor and a reference voltage to judge a magnitude of a current flowing through the output transistor; and a reference voltage generating circuit, wherein the reference voltage generating circuit includes a constant current circuit flowing a constant current and a resistance element having one terminal connected to a power source voltage terminal, the reference voltage generating circuit generating the reference voltage based on a power source voltage by the conversion of the constant current into a voltage by flowing the constant current through the resistance element.

Abstract: A power supply circuit is disclosed that includes a coil with first and second ends having supply voltage applied to the first end, a first switching element connected between the second end of the coil and ground, a second switching or diode element supplying current to a load after rectifying the current in accordance with voltage generated at the connection of the coil and the first switching element, a driver circuit switching at least the first switching element, a third switching element connected in series to the load, and a power supply stop circuit switching off the first element so as to stop supplying power to the load and switching off the third element so as to stop supplying the current to the load in accordance with an external signal.

Abstract: A power supply circuit is disclosed that includes a coil with first and second ends having supply voltage applied to the first end, a first switching element connected between the second end of the coil and ground, a second switching or diode element supplying current to a load after rectifying the current in accordance with voltage generated at the connection of the coil and the first switching element, a driver circuit switching at least the first switching element, a third switching element connected in series to the load, and a power supply stop circuit switching off the first element so as to stop supplying power to the load and switching off the third element so as to stop supplying the current to the load in accordance with an external signal.