Abstract: In a first light emission control device, a clock signal is generated, and after a first driving sequence starts to be performed in which the respective states of light-emitting elements in a first light-emitting element array are sequentially switched synchronously with the clock signal, at a particular time point a characteristic of the clock signal is changed from a first characteristic to a second characteristic. After the change, in a second light emission control device, a second driving sequence is performed in which the respective states of light-emitting elements in a second light-emitting element array are sequentially switched synchronously with the clock signal.

Abstract: A semiconductor integrated circuit for driving a light emitting element forms at least part of a light emitting element driving device configured to change the number of light emitting elements that are lit among a plurality of light emitting elements connected in series. The semiconductor integrated circuit includes a variable resistor controller configured to increase the resistance value of a variable resistor connected in series with the plurality of light emitting elements immediately before, or at the same time as, the time point at which the number of light emitting elements that are lit is reduced.

Abstract: In a first light emission control device, a clock signal is generated, and after a first driving sequence starts to be performed in which the respective states of light-emitting elements in a first light-emitting element array are sequentially switched synchronously with the clock signal, at a particular time point a characteristic of the clock signal is changed from a first characteristic to a second characteristic. After the change, in a second light emission control device, a second driving sequence is performed in which the respective states of light-emitting elements in a second light-emitting element array are sequentially switched synchronously with the clock signal.

Abstract: A semiconductor device comprises: a package having a rectangular shape when viewed in plan and including a first side, a second side parallel to the first side, a third side orthogonal to the first side and the second side, and a fourth side parallel to the third side and orthogonal to the first side and the second side; a power supply terminal provided on the first side; a power ground terminal provided on the second side; a switch output terminal provided on the second side; an upper switch connected between the power supply terminal and the switch output terminal; and a lower switch 11L connected between the switch output terminal and the power ground terminal.

Abstract: A ground fault detection circuit includes an input portion, and a ground fault determination unit. The input portion inputs an anode voltage of a series connection unit constituted of a plurality of light emission elements. When an anode voltage of the series connection unit input by the input portion is lower than or equal to a predetermined value less than a product of an on-resistance of the short-circuit switch disposed in parallel to each of the light emission elements and current supplied to the series connection unit, the ground fault determination unit determines that a ground fault has occurred without the short-circuit switch in a ground fault path.

Abstract: A switch driving device 10 comprises: multichannel switch elements SW1 to SW8 which are connected in parallel to a plurality of light-emitting elements included in a vehicle-mounted light-emitting device; and a logic portion 120 which automatically starts a series of switch driving sequence so that the on-off states of the switch elements SW1 to SW8 are sequentially switched in a predetermined pattern in response to the power-on of the device.

Abstract: A ground fault detection circuit includes an input portion, and a ground fault determination unit. The input portion inputs an anode voltage of a series connection unit constituted of a plurality of light emission elements. When an anode voltage of the series connection unit input by the input portion is lower than or equal to a predetermined value less than a product of an on-resistance of the short-circuit switch disposed in parallel to each of the light emission elements and current supplied to the series connection unit, the ground fault determination unit determines that a ground fault has occurred without the short-circuit switch in a ground fault path.

Abstract: A ground fault detection circuit includes an input portion, and a ground fault determination unit. The input portion inputs an anode voltage of a series connection unit constituted of a plurality of light emission elements. When an anode voltage of the series connection unit input by the input portion is lower than or equal to a predetermined value less than a product of an on-resistance of the short-circuit switch disposed in parallel to each of the light emission elements and current supplied to the series connection unit, the ground fault determination unit determines that a ground fault has occurred without the short-circuit switch in a ground fault path.

Abstract: A light emitting drive device has an output voltage supply unit, and an emergency drive unit. The output voltage supply unit generates an output voltage from an input voltage on the basis of a control signal transmitted from a control unit, and supplies at least one light emitting element with the output voltage. In the cases where the emergency drive unit received a signal indicating abnormality of the control unit, the emergency drive unit lights the whole or a part of the at least one light emitting element irrespective of the control signal transmitted from the control unit.

Abstract: A light emitting element driving semiconductor integrated circuit constitutes at least a part of a light emitting element driving device arranged to drive a series connection unit including a plurality of light emitting elements. The light emitting element driving semiconductor integrated circuit includes a single-element short-circuit detection unit arranged to detect that one of the plurality of light emitting elements is short-circuited, and a control unit arranged to control a power element of the light emitting element driving device so that current supplied from the light emitting element driving device to the series connection unit is increased, when the single-element short-circuit detection circuit detects that one of the plurality of light emitting elements is short-circuited.

Abstract: A light emitting drive device has an output voltage supply unit, and an emergency drive unit. The output voltage supply unit generates an output voltage from an input voltage on the basis of a control signal transmitted from a control unit, and supplies at least one light emitting element with the output voltage. In the cases where the emergency drive unit received a signal indicating abnormality of the control unit, the emergency drive unit lights the whole or a part of the at least one light emitting element irrespective of the control signal transmitted from the control unit.

Abstract: A light-emitting element driving device includes a reset signal generation unit that generates a reset signal in accordance with current flowing in a light-emitting element, a set signal generation unit that generates a set signal in accordance with the anode voltage of the light-emitting element, and an output voltage supply unit that generates an output voltage from an input voltage in accordance with the reset signal and the set signal, so as to supply the output voltage to the light-emitting element. The set signal generation unit includes a current generation unit that generates current according to the anode voltage of the light-emitting element, a charging unit that charges the current generated by the current generation unit, and a comparator that generates the set signal in accordance with a comparison result between a charging voltage of the charging unit and a reference voltage.

Abstract: A light emitting drive device has an output voltage supply unit, and an emergency drive unit. The output voltage supply unit generates an output voltage from an input voltage on the basis of a control signal transmitted from a control unit, and supplies at least one light emitting element with the output voltage. In the cases where the emergency drive unit received a signal indicating abnormality of the control unit, the emergency drive unit lights the whole or a part of the at least one light emitting element irrespective of the control signal transmitted from the control unit.

Abstract: A ground fault detection circuit includes an input portion, and a ground fault determination unit. The input portion inputs an anode voltage of a series connection unit constituted of a plurality of light emission elements. When an anode voltage of the series connection unit input by the input portion is lower than or equal to a predetermined value less than a product of an on-resistance of the short-circuit switch disposed in parallel to each of the light emission elements and current supplied to the series connection unit, the ground fault determination unit determines that a ground fault has occurred without the short-circuit switch in a ground fault path.

Abstract: A switch driving device 10 comprises: multichannel switch elements SW1 to SW8 which are connected in parallel to a plurality of light-emitting elements included in a vehicle-mounted light-emitting device; and a logic portion 120 which automatically starts a series of switch driving sequence so that the on-off states of the switch elements SW1 to SW8 are sequentially switched in a predetermined pattern in response to the power-on of the device.

Abstract: A light emitting device includes a series connection unit constituted of N light emitting elements, a light emitting element driving circuit having an output terminal connected to an anode of the series connection unit, N short-circuit switches respectively connected in parallel to the light emitting elements, and a switch control unit arranged to control on and off of the short-circuit switches. A ground fault detection circuit, which detects a ground fault of the light emitting device, includes a reference voltage source arranged to generate a reference voltage, and a comparator arranged to compare the anode voltage of the series connection unit with the reference voltage. The reference voltage has a value smaller than the product of an on-resistance of one of the short-circuit switches and output current of the light emitting element driving circuit.

Abstract: A light emitting element driving semiconductor integrated circuit constitutes at least a part of a light emitting element driving device arranged to drive a series connection unit including a plurality of light emitting elements. The light emitting element driving semiconductor integrated circuit includes a single-element short-circuit detection unit arranged to detect that one of the plurality of light emitting elements is short-circuited, and a control unit arranged to control a power element of the light emitting element driving device so that current supplied from the light emitting element driving device to the series connection unit is increased, when the single-element short-circuit detection circuit detects that one of the plurality of light emitting elements is short-circuited.

Abstract: A light emitting device includes a series connection unit constituted of N light emitting elements, a light emitting element driving circuit having an output terminal connected to an anode of the series connection unit, N short-circuit switches respectively connected in parallel to the light emitting elements, and a switch control unit arranged to control on and off of the short-circuit switches. A ground fault detection circuit, which detects a ground fault of the light emitting device, includes a reference voltage source arranged to generate a reference voltage, and a comparator arranged to compare the anode voltage of the series connection unit with the reference voltage. The reference voltage has a value smaller than the product of an on-resistance of one of the short-circuit switches and output current of the light emitting element driving circuit.

Abstract: A light emitting drive device has an output voltage supply unit, and an emergency drive unit. The output voltage supply unit generates an output voltage from an input voltage on the basis of a control signal transmitted from a control unit, and supplies at least one light emitting element with the output voltage. In the cases where the emergency drive unit received a signal indicating abnormality of the control unit, the emergency drive unit lights the whole or a part of the at least one light emitting element irrespective of the control signal transmitted from the control unit.

Abstract: A light-emitting element driving device includes a reset signal generation unit that generates a reset signal in accordance with current flowing in a light-emitting element, a set signal generation unit that generates a set signal in accordance with the anode voltage of the light-emitting element, and an output voltage supply unit that generates an output voltage from an input voltage in accordance with the reset signal and the set signal, so as to supply the output voltage to the light-emitting element. The set signal generation unit includes a current generation unit that generates current according to the anode voltage of the light-emitting element, a charging unit that charges the current generated by the current generation unit, and a comparator that generates the set signal in accordance with a comparison result between a charging voltage of the charging unit and a reference voltage.