Patent ID: 9000685
Filing Date: 2015-04-07
Classification: H05B

Abstract:
1. A light emitting device power supply circuit, for identifying an identifiable light emitting device circuit to determine whether to operate in an identified mode or a miss mode and supply an output current to the identifiable light emitting device circuit in the identified mode, wherein the identified mode indicates that the identifiable light emitting device circuit is normally coupled to the light emitting device power supply circuit, and the miss mode indicates that the identifiable light emitting device circuit is not normally coupled to the light emitting device power supply circuit, the light emitting device power supply circuit comprising: a power stage circuit, for operating at least one power switch therein according to an operation signal in the identified mode, to convert an input voltage to an output voltage, and supply the output current to the identifiable light emitting device circuit; a level control circuit, for controlling the output voltage at a predetermined level in the miss mode; an identification circuit, for determining whether the miss mode is changed to the identified mode according to whether the output voltage meets a predetermined condition, and generating an enable signal correspondingly; and an operation signal generation circuit, for generating the operation signal according to a feedback signal when the enable signal indicates the identified mode; wherein the identification circuit includes: a first comparison circuit, for generating a first comparison signal according to the output voltage and a first reference level, wherein the first reference level is higher than the predetermined level; a second comparison circuit, for generating a second comparison signal according to the output voltage and a second reference level, wherein the second reference level is lower than the predetermined level; and a determination circuit, which is coupled to the first comparison circuit and the second comparison circuit, and outputs the enable signal, wherein the determination circuit determines a level of the enable signal according to the first comparison signal and/or the second comparison signal.