In an LED driving device, a DC-DC controller performs control such that the voltage at an LED terminal remains equal to a reference voltage, and a reference voltage generator generates the reference voltage such that it decreases as the set value of the LED current set by an LED current setter decreases.

Disclosed herein are transconductance circuits, as well as related methods and devices. In some embodiments, a transconductance circuit may include an amplifier having a first input coupled to a voltage input of the transconductance circuit, and a switch coupled between an output of the amplifier and a second input of the amplifier.

Disclosed herein are transconductance circuits, as well as related methods and devices. In some embodiments, a transconductance circuit may include an amplifier having a first input coupled to a voltage input of the transconductance circuit, and a switch coupled between an output of the amplifier and a second input of the amplifier.

An expander circuit may be configured to control a plurality of driver circuits for driving light emitting diodes (LEDs). The expander circuit may comprise a bus interface circuit configured to receive control signals from a processor over a communication bus, and a plurality of modulation signal generators configured to generate modulation signals based on the control signals. The expander circuit may be configured to provide the modulation signals to the plurality of driver circuits for driving the LEDs.

An expander circuit may be configured to control a plurality of driver circuits for driving light emitting diodes (LEDs). The expander circuit may comprise a bus interface circuit configured to receive control signals from a processor over a communication bus, and a plurality of modulation signal generators configured to generate modulation signals based on the control signals. The expander circuit may be configured to provide the modulation signals to the plurality of driver circuits for driving the LEDs.

An RF controlled lighting unit is provided, suitable for connection to at least one of a dimmer for adjusting a phase cut angle of input mains voltage in accordance with an adjustable dimming level or an electronic switch for selecting between on- and off-states. The lighting unit includes a solid state light source; a radio circuit for receiving a wireless control signal; a rectifier circuit for rectifying the input mains voltage received from the electronic switch or the dimmer; a first power converter for driving the solid state light source in response to the rectified input mains voltage and delivering power to the radio circuit; and a second power convertor for delivering power to the radio circuit when the rectified input mains voltage becomes inadequate for the first power converter due to the phase-cut angle of the rectified input mains voltage or the off-state of the electronic switch.

A method and circuit to use light-emitting diodes to emulate the dimming performance of incandescent lighting, and more particularly, to making a circuit that uses only white and deep red light-emitting diodes to achieve a coordinated-color-temperature as a function of dim level that is close to that of an incandescent light being similarly dimmed.

A LED driver adopts one power stage to provide a constant drive current to drive a load, and to provide different power supply voltages to power a smart module according to a dimming signal input by users through the smart module. The LED driver provides high performance with simple circuit structure.

In order to make flexible, reliable lighting possible for industrial image processing, it is provided that a lighting unit (2), having a lighting device (5) comprising a number of light sources (6), receives a set value of the lighting via a data bus from a lighting control unit (10), that the lighting unit (2) captures a state variable (Z) of the lighting unit (2) and/or the surroundings of the lighting unit (2), and that the lighting unit (2) adjusts the set value in a closed control loop separately and independently from the lighting control unit (10) in that a control variable for at least one light source (6) is calculated in the lighting unit (2) and adjusted at the at least one light source (6).

A method for controlling an amount of power delivered to an electrical load may include controlling an average magnitude of a load current towards a target load current that ranges from a maximum-rated current to a minimum-rated current in a normal mode, and controlling the average magnitude of the load current below the minimum-rated current in a burst mode. The burst mode may include at least one burst-mode period that comprises a first time period associated with an active state and a second time period associated with an inactive state. During the burst mode, the method may include regulating a peak magnitude of the load current towards the minimum-rated current during the active state, and stopping the generation of at least one drive signal during the inactive state to control the average magnitude of the load current to be less than the minimum-rated current.