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US 9,320,097 B2Granted
Multi-string dimmable LED driver
AssigneeMarvell World Trade Ltd.
InventorsWanfeng Zhang, Pantas Sutardja
Life of this patent
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Abstract
An apparatus includes a first LED driver configured to control a first string of LEDs, a second LED driver configured to control a second string of LEDs, a third LED driver configured to control a third string of LEDs, and a control circuit configured to receive a control signal and to control the first, second, and third LED drivers so that the first, second, and third strings of LEDs cooperate in producing light according to the control signal and a color curve.
Claims19
An apparatus, comprising:
- a first LED driver configured to control a first string of LEDs;
- a second LED driver configured to control a second string of LEDs;
- a third LED driver configured to control a third string of LEDs;
- and
- a control circuit configured to receive a control signal and to control the first, second, and third LED drivers so that the first, second, and third strings of LEDs cooperate in producing light according to the control signal and a color curve stored in a color curve circuit of the control circuit,
- wherein the control circuit is configured to control each of the first and second LED drivers in a Pulse Width Modulation (PWM) mode configured to control duty cycles of currents of the respective strings of LEDs and in a linear mode configured to control magnitudes of the currents, and
- wherein the control circuit is operable to simultaneously control the first LED driver in the PWM mode and the second LED driver in the linear mode.
4 more elements
A method of controlling a plurality of strings of LEDs in a multi-string LED driver, the method comprising:
- receiving a control signal;
- determining a target value according to the control signal and a color curve stored in a color curve circuit;
- controlling an LED driver according to the target value so that the plurality of strings of LEDs cooperate in producing light according to the control signal and the color curve, wherein the LED driver is one of first through third LED drivers of the multi-string LED driver;
- and
- controlling a duty cycle of a current of a first string of LEDs of the plurality of strings of LEDs in a Pulse Width Modulation (PWM) mode, and simultaneously controlling a magnitude of a current of a second string of LEDs of the plurality of strings of LEDs in a linear mode.
2 more elements
Dependencies are inferred from the claim text.