Light-emitting diode packages with varying current pulse width modulation and related methods
AssigneeCreeLED, Inc.
InventorChristopher P. Hussell
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Abstract
Light-emitting diode (LED) packages and, more particularly, LED packages with varying current pulse width modulation (PWM) signals and related methods are disclosed. Varying current PWM is provided by having multiple current sources at different current levels for each LED chip in an LED package. An output PWM signal for each LED chip is routed to selectively turn on and off different combinations of current sources to provide varying current levels associated with varying brightness levels for each LED chip. By providing multiple current sources for each LED chip, the dynamic range of current levels and corresponding brightness levels may be increased for a same PWM clock frequency.
Claims22
A light-emitting diode (LED) package configured for receiving and transmitting digital communication signals, the LED package comprising:
- an LED chip;
- and
- an LED driver configured to drive the LED chip by pulse width modulation (PWM), the LED driver comprising a plurality of current sources configured to provide varying current levels to the LED chip, wherein the LED driver is configured to only adjust the current level provided to the LED chip during a single clock cycle of a PWM period.
A method of light output control within a light-emitting diode (LED) package, the method comprising:
- controlling brightness levels of an LED chip with pulse width modulation (PWM);
- and
- adjusting current levels to the LED chip during less than half of a PWM period, wherein the current levels are only adjusted for a single clock cycle of the PWM period.
A light-emitting device comprising:
- a light-emitting diode (LED) chip;
- and
- an LED driver configured to drive the LED chip by pulse width modulation (PWM), the LED driver comprising a plurality of current sources configured to provide varying current levels to the LED chip, wherein the LED driver is configured to only adjust the current level provided to the LED chip during a single clock cycle of a PWM period.
Dependencies are inferred from the claim text.