Patent ID: 8368312
Filing Date: 2013-02-05
Classification: H05B,Y02B

Abstract:
1. A light-emitting-diode driving circuit, comprising: a current driving circuit configured to control current signals flowing through light-emitting-diode strings in response to a first control signal that includes information of a light-emitting-diode current; a dynamic headroom controller configured to generate a third control signal that changes according to a change of the current signals flowing through the light-emitting-diode strings based on voltage signals of first terminals of each of the light-emitting-diode strings and a second control signal that includes the information of the light-emitting-diode current; and a power supply circuit configured to generate a light-emitting-diode driving voltage that changes in response to the third control signal, and provide the light-emitting-diode driving voltage to second terminals of each of the light-emitting-diode strings, wherein the dynamic headroom controller includes: a level detector configured to detect voltage levels of the voltage signals of the first terminals of each of the light-emitting-diode strings, and generate a minimum detection voltage signal having a minimum voltage level of the detected voltage levels; a reference voltage generating circuit configured to generate a first reference voltage that changes in response to the second control signal; and a comparator configured to compare the minimum detection voltage signal with the first reference voltage to generate the third control signal.