A light emitting diode (LED) driving device is provided. The LED driving device includes a rectifier configured to generate a rectified voltage, wherein the rectifier is directly connected to an input node of a light source including LEDs; a regulator configured to output a direct current (DC) power supply voltage using the rectified voltage; a microcontroller including a control terminal and a power terminal, wherein the microcontroller is configured to generate a dimming control signal based on a voltage input, receive the DC power supply voltage through the power terminal and output the dimming control signal through the control terminal; a driver configured to control an LED current to flow through the LEDs based on the dimming control signal; and a switch connected between a control node and a ground node, wherein an output terminal of the regulator and the control terminal are connected to the control node.

One example described herein includes a light-emitting diode (LED) driver system. The system includes an error amplifier configured to compare an input voltage with a reference voltage to generate a control voltage. The system further includes an amplifier output stage configured to control an output current through a first current path and a shunt current through a second current path based on the control voltage. The amplifier output stage comprises a slew-rate controller configured to control a slew-rate of the shunt current. The shunt current can be provided through a shunt resistor in the second current path and added to the output current to provide a total current through an LED string.

One example described herein includes a light-emitting diode (LED) driver system. The system includes an error amplifier configured to compare an input voltage with a reference voltage to generate a control voltage. The system further includes an amplifier output stage configured to control an output current through a first current path and a shunt current through a second current path based on the control voltage. The amplifier output stage comprises a slew-rate controller configured to control a slew-rate of the shunt current. The shunt current can be provided through a shunt resistor in the second current path and added to the output current to provide a total current through an LED string.

The invention provides an interconnected string of three LED modules, having internal and external connections such that each LED in the string is fully individually addressable. LED biases and interconnects are oriented and configured such that individual addressability is achieved without the need for direct external signal connections to each LED in the string. Consequently embodiments are provided comprising pluralities of strings, arranged so as to form an array of LED modules, wherein wiring tracks running beneath, or along the intermediary spaces between, rows of LEDs are not required. Hence are provided LED devices comprising an array of individually addressable LED modules, having reduced spacing between rows and columns, and having optimal thermal path perpendicularly across the substrate layer. Provided devices have improved heat dissipation and greater achievable LED array density. Also provided are embodiments comprising one or more lens arrangements, suitable, for example, for adaptive beam-shaping applications.

The present invention discloses a full voltage segmented linear constant-current LED drive circuit in an auto switchover mode, comprising a minimum two groups of LEDs in parallel connection in proper sequence and a voltage detection and control circuit used for detection of power voltage; positive terminal of each group of LEDs is directly connected or indirectly connected to the power source via the change-over switch; negative terminal of each group of LEDs is grounded via corresponding control switch; wherein, one group of LEDs comprises a minimum two groups of LED units in series connection in proper sequence; negative terminal of each LED unit is grounded via corresponding control switch; the change-over switch and control switch are connected to and controlled by the voltage detection and control circuit to change inter-group parallel connection mode and ON/OFF of different LED units. The drive circuit according to the present invention can switch over series and parallel connection mode of LED, which can also easily adjust total load current in time according to voltage fluctuation mode, and thereby reduce harmonic distortion, and cater to power factor.

A control circuit for a light emitting diode (LED) lighting system for achieving a dim-to-warm effect is provided. The control circuit includes an LED controller, a clamp circuit coupled to a set of warm correlated-color-temperature (“CCT”) LEDs, a switch coupled to a set of cool LEDs, and a feedback circuit coupled to the clamp and the switch. The LED controller is configured to control the clamp circuit to clamp current through the set of warm LEDs based on the input current, and control the switch to switch on the set of cool LEDs responsive to the input current being greater than a first threshold level and to switch off the set of cool LEDs responsive to the input current being lower than the first threshold level. The feedback circuit is configured to divert current from the set of warm LEDs to the set of cool LEDs.

A light emitting diode (“LED”) module is disclosed. The LED module includes a first LED tap and a second LED tap, the first tap being powered on for a longer amount of time than the second LED tap, based on an alternating current voltage. The LED module also includes a first LED package on which a first LED associated with the first LED tap and a second LED associated with the second LED tap are disposed. The LED module further includes a second LED package on which a third LED associated with the first LED tap and a fourth LED associated with the second LED tap are disposed.

A lighting unit (100) includes light emitting diode (LED) modules (120, 300) and a lighting driver (110, 200) connected to the LED modules. Each LED module includes LEDs (323) and an identification current source (324) supplying an identification current to an identification current output node (180, 380). All of the identification current output nodes are connected together to supply a total identification current having a magnitude which changes in response to the number of LED modules that are connected to the lighting driver. The lighting driver includes: a controllable current source (220 & 250) to supply an LED driving current to the LEDs of the LED modules, and a controller (230) that responds to the total identification current to control the controllable current source to supply the LED driving current at a magnitude which changes in response to the number of LED modules that are connected to the lighting driver.

An LED driver circuit includes a rectifying module, a control unit, and at least two LED light strings. The control unit includes a voltage input detection terminal and a switch assembly. The voltage input detection terminal is configured to detect the waveform of the voltage input. The switch assembly changes the way of connection between the LED light strings according to the waveform of the voltage input.

A light-emitting element driving semiconductor integrated circuit constitutes at least part of a light-emitting element driving device that is configured to drive a first and a second light source when the first light source is not short-circuited and drive the second light source when the first light source is short-circuited and that includes an output capacitor. The light-emitting element driving semiconductor integrated circuit has a controller configured to control the resistance value of a variable resistor connected in series with the first and second light sources according to the voltage across a resistor connected in series with the first and second light sources.