A control circuit includes: an output terminal configured to be coupled to a control terminal of a transistor that has a current path coupled to an inductor; a transconductance amplifier configured to produce a sense current based on a current flowing through the current path of the transistor; and a first capacitor, where the control circuit is configured to: turn on the transistor based on a clock signal, integrate the sense current with an integrating capacitor to generate a first voltage, generate a second voltage across the first capacitor based on a first current, generate a second current based on the second voltage, generate a third voltage based on the second current, turn off the transistor when the first voltage becomes higher than the third voltage; discharge the integrating capacitor when the transistor turns off; and regulate an average output current flowing through the inductor based on the first current.

The present application provides a color LED driving circuit, which comprises a set of switches and a color controller. The switch assembly has a first switch and a second switch, respectively having a first terminal, a second terminal and a control terminal. The first terminal of the first switch is configured to be coupled to a first LED load, and the first terminal of the second switch is configured to be coupled to a second LED load. The color controller comprises a first controller and a second controller. A ground terminal of the first controller is coupled to ground. The first controller is used to generate an output signal according to a PWM signal, and transmit the output signal to the second controller. The second controller is used to generate a first driving signal and a second driving signal according to the output signal, and output the first driving signal and the second driving signal to the control terminals of the first switch and the second switch through a first driving terminal and a second driving terminal, respectively. A reference terminal of the second controller is coupled to the second terminal of the first switch and the second terminal of the second switch, and potential of the reference terminal is different from a potential of the ground terminal of the first controller.

The present application provides a color LED driving circuit, which comprises a set of switches and a color controller. The switch assembly has a first switch and a second switch, respectively having a first terminal, a second terminal and a control terminal. The first terminal of the first switch is configured to be coupled to a first LED load, and the first terminal of the second switch is configured to be coupled to a second LED load. The color controller comprises a first controller and a second controller. A ground terminal of the first controller is coupled to ground. The first controller is used to generate an output signal according to a PWM signal, and transmit the output signal to the second controller. The second controller is used to generate a first driving signal and a second driving signal according to the output signal, and output the first driving signal and the second driving signal to the control terminals of the first switch and the second switch through a first driving terminal and a second driving terminal, respectively. A reference terminal of the second controller is coupled to the second terminal of the first switch and the second terminal of the second switch, and potential of the reference terminal is different from a potential of the ground terminal of the first controller.

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.

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.

A lighting apparatus includes a bridge circuit, a current source, a first LED module, a second LED module and a switch. The bridge circuit is used for rectifying an input AC power to generate a DC power. The current source receives the DC power to generate a driving current. The first LED module emits a first light of a first color temperature. The second LED module emits a second light of a second color temperature. The switch is coupled to the current source to change at least a resistance parameter corresponding to a current ratio between the first LED module and the second LED module to generate a mixed light of a mixed color temperature.

A lighting apparatus includes a bridge circuit, a current source, a first LED module, a second LED module and a switch. The bridge circuit is used for rectifying an input AC power to generate a DC power. The current source receives the DC power to generate a driving current. The first LED module emits a first light of a first color temperature. The second LED module emits a second light of a second color temperature. The switch is coupled to the current source to change at least a resistance parameter corresponding to a current ratio between the first LED module and the second LED module to generate a mixed light of a mixed color temperature.

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 example headlight includes: a multi-segment illumination source comprising: a first illumination source segment; and a second illumination source segment; driver circuitry coupled to the multi-segment illumination source, the driver circuitry comprising: a first driver coupled to the first illumination source segment, the first driver configured to generate a first drive signal to cause the first illumination source segment to produce a first light having a first brightness; and a second driver coupled to the second illumination source segment, the second driver configured to generate a second drive signal to cause the second illumination source segment to produce a second light having a second brightness; and a spatial light modulator (SLM) optically coupled to the multi-segment illumination source, the SLM configured to: receive the first light; modulate the first light to produce first modulated light; receive the second light; and modulate the second light to produce second modulated light.