A MOSFET circuit clamps a MOSFET gate voltage (either directly or via a gate control circuit) when the source voltage exceeds a threshold level, for example in response to a voltage surge event between the source and drain. In particular, the gate is held at a voltage relative to the source, to turn off the first MOSFET during such a surge event, but not during normal operation. This provides automatic protection against unwanted increases in the input voltage, especially when the MOSFET was in its on state during the switching. A threshold circuit is connected between a gate (or gate control node) and a reference voltage. When the voltage at the source exceeds a voltage threshold level, it conduct a unidirectional circuit component (D18) between the source and gate (or gate control node), and the threshold circuit.

A variable light distribution light source includes an array-type light-emitting device. The array-type light-emitting device includes a power supply terminal and multiple pixel circuits electrically coupled and spatially arranged in a matrix. A power supply circuit includes a power supply unit that supplies electric power to the array-type light-emitting device. An output of a DC/DC converter is coupled to the power supply terminal VDD of the array-type light-emitting device via an output terminal. A voltage setting circuit generates a controllable correction voltage. A feedback circuit generates a feedback voltage based on the correction voltage and the control target voltage that corresponds to the output voltage of the DC/DC converter, and supplies the feedback voltage to a feedback pin of a converter controller.

A light emitting diode (LED) driving device for driving an LED array including one or more LEDs includes a rectifier configured to provide a rectified voltage obtained from an alternating current (AC) voltage to the LED array, an LED driver configured to sequentially drain an LED driving current from the LED array via a plurality of first nodes, and a first switch circuit connected to the LED array via a plurality of second nodes. The first switch circuit includes a plurality of first switches commonly connected to a first common node which is one of the plurality of first nodes, and respectively connected to the plurality of second nodes, and a first controller configured to control the plurality of first switches to be sequentially turned on and sequentially turned off.

A light emitting diode (LED) driving device for driving an LED array including one or more LEDs includes a rectifier configured to provide a rectified voltage obtained from an alternating current (AC) voltage to the LED array, an LED driver configured to sequentially drain an LED driving current from the LED array via a plurality of first nodes, and a first switch circuit connected to the LED array via a plurality of second nodes. The first switch circuit includes a plurality of first switches commonly connected to a first common node which is one of the plurality of first nodes, and respectively connected to the plurality of second nodes, and a first controller configured to control the plurality of first switches to be sequentially turned on and sequentially turned off.

A single channel-based multi-functional light emitting diode lamp driving system includes: first and second light source groups distinguished for each lamp function thereof; a single LED lamp driving module adjusting an input voltage to a voltage required for each lamp function and to apply it to the first and second light source groups; a switching module controlling on or off of the first and second light source groups; and a control module controlling light amounts of the first and second light source groups by performing time-division control on an on or off time of the switching module in conjunction with the LED lamp driving module, wherein the control module is configured to perform time division turn-on control on the first and second light source groups by controlling at least one of a current value applied to the first and second light source groups or a duty ratio thereof in a high-beam passing mode.

Techniques and architecture are disclosed for array of light emitting diodes. For example, the array may comprise a plurality of stages, each stage comprising a plurality of light emitting diodes (LEDs) connected to a floating switch, respectively. The LEDs may be arranged substantially linearly on a circuit board in a plurality of clusters, where a distance between adjacent LEDs within a cluster is smaller than a distance between LEDs in adjacent clusters. Adjacent clusters contain LEDs from different stages and each stage contains LEDs in different clusters. The array may be incorporated in a lighting system. The light system may have a closed loop feedback mechanism which directly detects light emitted from a subset of the LEDs and a controller which controls the array based on the detection.

A light emitting diode (LED) device is provided. The LED device a first LED string configured to emit light having a first color temperature; a second LED string connected to the first LED string in parallel, and configured to emit light having a second color temperature different from the first color temperature; a controller configured to generate a control signal based on a control command received from an external controller; a switching circuit configured to control brightness of any one or any combination of the first LED string and the second LED string based on the control signal; and a power supply configured to generate an internal power voltage for operation of the controller and the switching circuit.

A light emitting diode (LED) device is provided. The LED device a first LED string configured to emit light having a first color temperature; a second LED string connected to the first LED string in parallel, and configured to emit light having a second color temperature different from the first color temperature; a controller configured to generate a control signal based on a control command received from an external controller; a switching circuit configured to control brightness of any one or any combination of the first LED string and the second LED string based on the control signal; and a power supply configured to generate an internal power voltage for operation of the controller and the switching circuit.

A device may include a light-emitting diode (LED) array including a plurality of LEDs, a rectifier configured to supply an input voltage rectified from an AC voltage to the LED array, an LED driver configured to drain an LED driving current from the LED array, and a current distributor configured to sense a first current passing through at least one first LED from among the plurality of LEDs and supply a second current to at least one second LED from among the plurality of LEDs based on the first current.

A device may include a light-emitting diode (LED) array including a plurality of LEDs, a rectifier configured to supply an input voltage rectified from an AC voltage to the LED array, an LED driver configured to drain an LED driving current from the LED array, and a current distributor configured to sense a first current passing through at least one first LED from among the plurality of LEDs and supply a second current to at least one second LED from among the plurality of LEDs based on the first current.