# US 9,521,719 B2 · Circuit for driving lighting apparatus and method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,521,719 B2 - Document ID: US9521719B2 - Status: Granted - Kind: B2 - Application number: 14/813,439 - Filed: 2015-07-30 - Published: 2016-03-17 - Granted: 2016-12-13 - Earliest claimed: 2014-09-15 - Assignees: MagnaChip Semiconductor, Ltd. - Applicants: Magnachip Semiconductor, Ltd. - Inventors: Gyu Ho Lim; Tae Il Yun; Beom Seon Ryu - Web page: https://patentgrep.com/patent/US9521719B2 ## CPC - H05B 45/3725: Switched mode power supply [SMPS] - H05B 45/395: Linear regulators - Y02B 20/30: Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED] - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A circuit for driving a lighting apparatus is provided. The circuit includes a valley signal generator configured to generate a valley signal based on an input voltage, an input voltage determining unit configured to determine whether the input voltage corresponds to a direct voltage or a full-wave rectified AC voltage based on the valley signal, an AC voltage simulation unit configured to generate a virtual valley signal when the input voltage is a DC voltage, and a switching device controller configured to control a switching device used to drive an LED module based the determination and at least one of the valley signal and virtual valley signal. ## Claims ### Claim 1 A circuit for driving a lighting apparatus, comprising: a valley signal generator configured to generate a valley signal based on an input voltage; an input voltage determining unit configured to determine whether the input voltage corresponds to a direct current (DC) voltage or a full-wave rectified AC voltage based on the valley signal; an AC voltage simulation unit configured to generate a virtual valley signal when the input voltage is a DC voltage; and a switching device controller configured to control a switching device used to drive an LED module based on a result of the determination by the input voltage determining unit and at least one of the valley signal and the virtual valley signal. ### Claim 2 (depends on 1) The circuit for driving a lighting apparatus of claim 1, further comprising: a driving voltage controller configured to receive a reference voltage from an external source and a driving voltage from a driving current sensing device, and control the driving voltage based on the reference voltage. ### Claim 3 (depends on 1) The circuit for driving a lighting apparatus of claim 1, wherein the valley signal generator comprises: an input voltage detection module configured to receive an input signal from an external power supply to detect the input voltage; a comparison module configured to compare the input voltage having a first voltage range and an internal reference voltage having a second voltage range to output a voltage having a third voltage range; and a noise removal module configured to receive an output voltage of the comparison module and an internal clock signal, and remove noise from the valley signal through a plurality of noise filters at each period of the internal clock signal. ### Claim 4 (depends on 3) The circuit for driving a lighting apparatus of claim 3, wherein the valley signal generator is further configured to generate a first valley signal that is output in a high level and a low level when the input voltage corresponds to an AC voltage, and a second valley signal that is output in a high level when the input voltage corresponds to a DC voltage. ### Claim 5 (depends on 4) The circuit for driving a lighting apparatus of claim 4, wherein the AC voltage simulation unit is further configured to substitute the virtual valley signal for the second valley signal. ### Claim 6 (depends on 1) The circuit for driving a lighting apparatus of claim 1, wherein the switching device controller is further configured to enable a driving current to flow to an inductor when the switching device is turned on, and enable a current charged in the inductor to flow to an LED module through a diode when the switching device is turned off. ### Claim 7 A method for driving a lighting apparatus, comprising: generating a valley signal based on an input voltage; determining whether the input voltage corresponds to a direct current (DC) voltage or a full-wave rectified AC voltage based on the valley signal; generating a virtual valley signal when the input voltage is a DC voltage; and controlling a switching device used to drive an LED module based on a result of the determining and at least one of the valley signal and the virtual valley signal. ### Claim 8 (depends on 7) The method for driving a lighting apparatus of claim 7, further comprising: receiving a reference voltage from an external source and a driving voltage from a driving current sensing device to control the driving voltage based on the reference voltage. ### Claim 9 (depends on 7) The method for driving a lighting apparatus of claim 7, wherein generating a valley signal based on an input voltage comprises: receiving an input signal from an external power supply to detect the input voltage; comparing the input voltage having a first voltage range and an internal reference voltage having a second voltage range to output a voltage having a third voltage range; and receiving the output voltage having the third voltage range and an internal clock signal, and removing noise from the valley signal through a plurality of noise filters. ### Claim 10 (depends on 7) The method for driving a lighting apparatus of claim 7, wherein controlling the switching device used to drive an LED module based on the result of the determining and at least one of the valley signal and virtual valley signal comprises: enabling a driving current to flow to an inductor when the switching device is turned on; and enabling a current charged in the inductor to flow to an LED module through a diode when the switching device is turned off. ### Claim 11 A lighting circuit comprising: a driving circuit configured to generate a valley signal in response to receiving an AC voltage and a virtual valley signal in response to receiving a DC voltage, and control a switching device that provides a driving current when switched on based on at least one of the valley signal and the virtual valley signal; and a light emitting diode (LED) unit configured to receive the driving current at an inductor when the switching device is switched on, wherein the inductor acts as a current source to an LED module when the switching device is switched off. ### Claim 12 (depends on 11) The lighting circuit of claim 11, wherein the driving circuit further comprises: a valley signal generator configured to generate the valley signal based on when the AC voltage is received; an input voltage determining unit configured to determine whether an input voltage corresponds to the AC voltage or the DC voltage based on the valley signal, wherein the AC voltage is a full-wave rectified AC voltage; an AC voltage simulation unit configured to generate the virtual valley signal based on the determination that the DC voltage is received; and a switching device controller configured to control the switching device used to drive the LED module based on a result of the determination by the input voltage determining unit and at least one of the valley signal and the virtual valley signal. ### Claim 13 (depends on 11) The lighting circuit of claim 11, wherein the driving circuit further comprises: a driving voltage controller configured to receive a reference voltage from an external source and a driving voltage from a driving current sensing device, and control the driving voltage based on the reference voltage. ### Claim 14 (depends on 12) The lighting circuit of claim 12, wherein the valley signal generator comprises: an input voltage detection module configured to receive an input signal from an external power supply to detect the input voltage; a comparison module configured to compare the input voltage having a first voltage range and an internal reference voltage having a second voltage range to output a voltage having a third voltage range; and a noise removal module configured to receive an output voltage of the comparison module and an internal clock signal, and remove noise from the valley signal through a plurality of noise filters at each period of the internal clock signal.