LED current control in a dimmable LED illumination system
First Claim
1. A light-emitting diode (LED) driver that drives a LED to a brightness level, comprising:
- a power processing stage, coupled to receive an ac signal, the power processing stage generating a boost voltage that is substantially a dc voltage, the duty cycle of the ac signal being modulated according to a dimmer input that is associated with the brightness level;
a current generator, coupled to the power processing stage, the current generator converting the boost voltage to a LED current according to a LED current control that determines the level of the LED current, the LED current being substantially a direct current that drives the LED to the brightness level; and
a LED current programming stage, coupled to the power processing page, the LED current programming stage sensing the boost voltage and generating the LED current control.
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Accused Products
Abstract
The invention relates to a light emitting diode (“LED”) illumination system, and more particularly, to systems, devices and methods of driving a LED module by a current generator that is powered and controlled by a regulated dc voltage associated with a brightness level. Such a dimmable LED illumination system is compatible with both a high-voltage ac signal coupled from any wall outlet and a low-voltage ac signal provided by an electronic transformer. A diode bridge rectifies the ac signal to a rectified ac signal, and a LED driver generates the LED current from the rectified ac signal and drives the LED to the brightness level. Within the LED driver, the level of the LED current is determined from a boost voltage that is substantially a regulated dc voltage generated from the rectified ac signal.
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Citations
20 Claims
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1. A light-emitting diode (LED) driver that drives a LED to a brightness level, comprising:
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a power processing stage, coupled to receive an ac signal, the power processing stage generating a boost voltage that is substantially a dc voltage, the duty cycle of the ac signal being modulated according to a dimmer input that is associated with the brightness level; a current generator, coupled to the power processing stage, the current generator converting the boost voltage to a LED current according to a LED current control that determines the level of the LED current, the LED current being substantially a direct current that drives the LED to the brightness level; and a LED current programming stage, coupled to the power processing page, the LED current programming stage sensing the boost voltage and generating the LED current control. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A light-emitting diode (LED) illumination system, comprising:
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a light-emitting diode (LED) that is driven by a LED current to a brightness level, the LED current being substantially a direct current; a diode bridge, coupled to receive an ac signal, the diode bridge rectifying the ac signal to a unidirectional ac signal; and a LED driver, coupled between the diode bridge and the LED, the LED driver generating the LED current from the rectified ac signal, the level of the LED current being determined from a boost voltage that is substantially a dc voltage generated from the rectified ac signal. - View Dependent Claims (13, 14, 15)
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16. A method of driving a light-emitting diode (LED) to a brightness level, comprising:
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rectifying an ac signal, the duty cycle of the ac signal being modulated according to a dimmer input that is associated with the brightness level; generating a boost voltage from the rectified ac signal, the boost voltage being substantially a dc voltage; generating a LED current control according to the boost voltage; and power a current generator using the boost voltage to generate a LED current, the current generator being controlled by the LED current control, the LED current being substantially a direct current that drives the LED to the brightness level. - View Dependent Claims (17, 18, 19, 20)
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Specification