# US 9,439,249 B2 · LED lighting apparatus for use with AC-output lighting ballasts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,439,249 B2 - Document ID: US9439249B2 - Status: Granted - Kind: B2 - Application number: 13/943,455 - Filed: 2013-07-16 - Published: 2014-07-24 - Granted: 2016-09-06 - Earliest claimed: 2013-01-24 - Assignees: Cree, Inc. - Applicants: Cree, Inc. - Inventors: Jun Zhang; James Andrew McBryde - Web page: https://patentgrep.com/patent/US9439249B2 ## CPC - F21K 9/27: Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes - H05B 45/385: using flyback topology - F21Y 2103/10: comprising a linear array of point-like light-generating elements - F21Y 2107/90: on two opposite sides of supports or substrates - F21Y 2115/10: Light-emitting diodes [LED] - Y02B 20/30: Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED] - F21K: NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An apparatus for interfacing a ballast to at least one light emitting diode (LED) includes a passive rectifier circuit and matching circuit coupled to an input port and/or an output port of the passive rectifier circuit and configured to at least partially match an impedance of the ballast. ## Claims ### Claim 1 An apparatus for interfacing a ballast to at least one light emitting diode (LED), the apparatus comprising: a passive rectifier circuit; and a matching circuit coupled at an input port and/or an output port of the passive rectifier circuit and configured to at least partially match an impedance of the ballast, wherein the at least one LED is provided in a housing and mounted on a substrate contained within a translucent portion of the housing, wherein the housing comprises non-translucent first and second end caps that cap respective ones of the first and second ends of the elongated housing and wherein the passive rectifier circuit and the matching circuit are at least partially contained within at least one of the first and second end caps. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the matching circuit is configured to couple the at least one LED to the passive rectifier circuit. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the passive rectifier circuit is configured to couple the at least one LED to the matching circuit. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the matching circuit comprises components on input and output sides of the passive rectifier circuit. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the matching circuit comprises at least one inductor and/or at least one capacitor. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the matching circuit comprises at least one inductor coupled in series with an input of the passive rectifier circuit and/or an output of the passive rectifier circuit. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the matching circuit comprises at least one capacitor coupled at an output of the passive rectifier circuit and/or at an input of the passive rectifier circuit. ### Claim 8 (depends on 1) The apparatus of claim 1, further comprising a transformer configured to couple the passive rectifier circuit to the ballast. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the matching circuit comprises an inductance of the transformer. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the matching circuit comprises at least one capacitor coupled across an input of the passive rectifier circuit and/or across an output of the passive rectifier circuit. ### Claim 11 (depends on 8) The apparatus of claim 8, wherein the matching circuit couples the transformer to the passive rectifier circuit. ### Claim 12 (depends on 8) The apparatus of claim 8, wherein the passive rectifier circuit couples the transformer to the matching circuit. ### Claim 13 (depends on 8) The apparatus of claim 8, wherein the matching circuit comprises components on input and output sides of the passive rectifier circuit. ### Claim 14 A lamp comprising: an elongated housing; at least one electrical contact positioned proximate at least one of first and second ends of the housing; at least one light emitting diode (LED) positioned in the housing and configured to provide illumination through at least one translucent portion of the housing between the first and second ends; a substrate contained within the housing, wherein the at least one LED is mounted on the substrate; and an impedance matching passive rectifier circuit at least partially contained within the housing and coupled to the at least one LED and the at least one electrical contact, wherein the housing comprises first and second non-translucent end caps that cap respective ones of the first and second ends of the elongated housing and wherein the impedance matching passive rectifier circuit is at least partially contained within at least one of the first and second end caps. ### Claim 15 (depends on 14) The lamp of claim 14, wherein the impedance matching passive rectifier circuit comprises first and second portions contained within respective ones of the first and second end caps. ### Claim 16 (depends on 14) The lamp of claim 14, wherein at least a portion of the impedance matching passive rectifier circuit is mounted on the substrate. ### Claim 17 (depends on 16) The lamp of claim 16, wherein the substrate comprises a flexible substrate.