Lighting units, lighting unit controls and lighting control methods are described herein. In various embodiments, a lighting unit (100, 500, 600, 700) may include a first light source (106, 06, 606, 706) that is adjustable to emit first light having a range of levels of a particular lighting property, such as brightness, saturation or hue. The lighting unit may further include a second light source (108, 508, 608, 708) that automatically, and independently of the first light source, transitions between a plurality of states in which the second light source emits second light at a plurality of levels of the particular lighting property that collectively form a dynamic effect.

In accordance with an embodiment, a switched-mode power converter includes a switch, a freewheeling diode coupled between an output terminal of the switch and a power supply input node, an inductor coupled between the output terminal of the switch and a power supply output node, and a passive network having a first terminal coupled to the output terminal of the switch, a second terminal coupled to a power supply output node, and a third terminal coupled to a reference terminal of the switch. A method includes measuring a first voltage at a fourth terminal of the passive network when the switch is on; measuring a second voltage at the fourth terminal of the passive network when the switch is off; and estimating an output voltage between the power supply output node and the reference terminal of the switch based on the first voltage and the second voltage.

Techniques are disclosed for regulating the temperature of a plurality of light-emitting diodes (LEDs) by monitoring the voltage drop across the LEDs. In one example, a driver circuit supplies a constant driver current to the LEDs. A temperature regulation circuit monitors the voltage drop across the LEDs to determine whether the junction temperature of the LEDs exceeds a maximum operating temperature. If the junction temperature of the LEDs exceeds the maximum operating temperature, the temperature regulation circuit uses digital pulse-width modulation (DPWM) to decrease a digital duty cycle of the driver current supplied to the LEDs.

A circuit and method of splitting or mirroring a primary current into multiple branches, nominally four, such that the current in each branch does not exceed a given maximum value, nominally 700 mA, and having good current-matching performance given a relatively high-frequency PWM input signal, on the order of 1 kHz, for use in a high-efficiency LED lighting system.

A circuit and method of splitting or mirroring a primary current into multiple branches, nominally four, such that the current in each branch does not exceed a given maximum value, nominally 700 mA, and having good current-matching performance given a relatively high-frequency PWM input signal, on the order of 1 kHz, for use in a high-efficiency LED lighting system.

A driving device comprises a first transistor (B13), a second transistor (B14), and a resistance element. The first transistor (B13) has one terminal receiving a pulsed current and a control terminal connected to the one terminal. The second transistor (B14) has one terminal connected to at least one load, the other terminal connected to a reference potential together with the other terminal of the first transistor (B13), and a control terminal connected to the control terminal of the first transistor (B13). The resistance element is connected between the control terminal of the first transistor (B13) and the other terminal of the first transistor (B13).

A driving device comprises a first transistor (B13), a second transistor (B14), and a resistance element. The first transistor (B13) has one terminal receiving a pulsed current and a control terminal connected to the one terminal. The second transistor (B14) has one terminal connected to at least one load, the other terminal connected to a reference potential together with the other terminal of the first transistor (B13), and a control terminal connected to the control terminal of the first transistor (B13). The resistance element is connected between the control terminal of the first transistor (B13) and the other terminal of the first transistor (B13).

An LED light fixture includes one or more optical transceivers that have a light support having a plurality of light emitting diodes and one or more photodetectors attached thereto, and a processor in communication with the light emitting diodes and the one or more photodetectors. The processor is constructed and arranged to generate a communication or data transfer signal.

An embodiment LED driver system comprises a power transistor configured to be selectively activated for generating a driving current for an array of LEDs, the power transistor having a first conduction terminal coupled to the array of LEDs and a second conduction terminal coupled to a reference resistor; an operational amplifier having a non-inverting input for receiving a reference voltage, an inverting input coupled to the second conduction terminal of the power transistor, and an output terminal coupled to a first conduction terminal of a transmission gate having a second conduction terminal coupled to a control terminal of the power transistor and a control terminal for receiving an enable signal; and a slew rate control unit configured to control the slew rate of the driving current.

An embodiment LED driver system comprises a power transistor configured to be selectively activated for generating a driving current for an array of LEDs, the power transistor having a first conduction terminal coupled to the array of LEDs and a second conduction terminal coupled to a reference resistor; an operational amplifier having a non-inverting input for receiving a reference voltage, an inverting input coupled to the second conduction terminal of the power transistor, and an output terminal coupled to a first conduction terminal of a transmission gate having a second conduction terminal coupled to a control terminal of the power transistor and a control terminal for receiving an enable signal; and a slew rate control unit configured to control the slew rate of the driving current.