# US 10,504,434 B2 · DC-DC converter and display device having the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,504,434 B2 - Document ID: US10504434B2 - Status: Granted - Kind: B2 - Application number: 14/797,501 - Filed: 2015-07-13 - Published: 2016-09-08 - Granted: 2019-12-10 - Earliest claimed: 2015-03-03 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Hak-Ki Choi - Web page: https://patentgrep.com/patent/US10504434B2 ## CPC - G09G 3/3258: with pixel circuitry controlling the voltage across the light-emitting element - G09G 3/2003: {Display of colours (specific for liquid crystal displays G09G3/3607)} - G09G 3/3225: using an active matrix - H02M 1/36: Means for starting or stopping converters - H02M 3/155: using semiconductor devices only - H02M 3/158: including plural semiconductor devices as final control devices for a single load - G09G 2330/02: Details of power systems and of start or stop of display operation - G09G 2330/027: Arrangements or methods related to powering off a display - G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD - H02M 1/008: {Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators} - H02M 1/322: {Means for rapidly discharging a capacitor of the converter for protecting electrical components or for preventing electrical shock} - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract A DC-DC converter includes a plurality of converters and a discharging circuit. The converters convert an input power voltage from an input terminal to a plurality of output power voltages for output to a plurality of output terminals. The discharging circuit is between the input terminal and the converters and discharges of voltages of the output terminals based on a discharging control signal. ## Claims ### Claim 1 A DC-DC converter having an input terminal and a plurality of output terminals, comprising: a plurality of converters to convert an input power voltage at the input terminal to a plurality of output power voltages at the plurality of output terminals; and a single discharging circuit between the input terminal and the converters, the single discharging circuit to discharge the plurality of output power voltages at the plurality of output terminals based on a single discharging control signal, wherein the single discharging circuit includes: a first switch between a first node directly connected to the converters and a reference terminal, the first switch to turn on based on the single discharging control signal, and a second switch between the input terminal and the first node, the second switch to turn off based on the single discharging control signal, wherein, while the single discharging control signal is applied, the plurality of output terminals are connected to the reference terminal through the first switch such that the plurality of output power voltages at the plurality of output terminals are substantially simultaneously discharged through the first switch of the single discharging circuit. ### Claim 2 (depends on 1) The DC-DC converter as claimed in claim 1, wherein the first switch and the second switch are transistors of different types from each other. ### Claim 3 (depends on 1) The DC-DC converter as claimed in claim 1, further comprising: an input capacitor between the first node and the reference terminal. ### Claim 4 (depends on 1) The DC-DC converter as claimed in claim 1, further comprising: an input capacitor between the input terminal and the reference terminal. ### Claim 5 (depends on 1) The DC-DC converter as claimed in claim 1, further comprising: a plurality of output capacitors, wherein each of the output capacitors is between a respective one of the output terminals and the reference terminal. ### Claim 6 (depends on 1) The DC-DC converter as claimed in claim 1, wherein each of the converters includes: a switching circuit including a plurality of switches and at least one inductor; and a switch controller to control switching operations of the plurality of switches to convert the input power voltage to one of the output power voltages. ### Claim 7 (depends on 6) The DC-DC converter as claimed in claim 6, wherein the switching circuit includes: a third switch between the single discharging circuit and a second node; a fourth switch between the second node and the reference terminal; and a first inductor between the second node and one of the output terminals. ### Claim 8 (depends on 6) The DC-DC converter as claimed in claim 6, wherein the switching circuit includes: a fifth switch between the single discharging circuit and a third node; a second inductor between the third node and the reference terminal; and a sixth switch between the third node and one of the output terminals. ### Claim 9 (depends on 6) The DC-DC converter as claimed in claim 6, wherein the switching circuit includes: a third inductor between the single discharging circuit and a fourth node; a seventh switch between the fourth node and the reference terminal; and an eighth switch between the fourth node and one of the output terminals. ### Claim 10 (depends on 6) The DC-DC converter as claimed in claim 6, wherein the switch controller is to control the switching circuit to connect the output terminals to the single discharging circuit based on the single discharging control signal. ### Claim 11 (depends on 1) The DC-DC converter as claimed in claim 1, wherein the plurality of second power voltages are power voltages for different color pixels. ### Claim 12 A display device, comprising: a display panel including a plurality of pixels; a scan driver to provide a scan signal to the pixels; a data driver to provide a data signal to the pixels; and a DC-DC converter to generate a plurality of output power voltages to be provided to the pixels, and having an input terminal and a plurality of output terminals, wherein the DC-DC converter includes: a plurality of converters to convert an input power voltage at the input terminal to the plurality of output power voltages at the plurality of output terminals; and a single discharging circuit between the input terminal and the converters, the single discharging circuit to discharge the plurality of output power voltages at the plurality of output terminals based on a single discharging control signal, wherein the single discharging circuit includes: a first switch between a first node directly connected to the converters and a reference terminal, the first switch to turn on based on the single discharging control signal, and a second switch between the input terminal and the first node, the second switch to turn off based on the single discharging control signal, wherein, while the single discharging control signal is applied, the plurality of output terminals are connected to the reference through the first switch of the single discharging circuit such that the plurality of output power voltages at the plurality of output terminals are substantially simultaneously discharged through the first switch of the single discharging circuit. ### Claim 13 (depends on 12) The display device as claimed in claim 12, wherein the DC-DC converter further includes an input capacitor between the first node and a reference terminal. ### Claim 14 (depends on 12) The display device as claimed in claim 12, wherein the DC-DC converter further includes an input capacitor between the input terminal and a reference terminal. ### Claim 15 (depends on 12) The display device as claimed in claim 12, wherein the DC-DC converter further includes: a plurality of output capacitors, wherein each of the output capacitors is between a respective one of the output terminals and a reference terminal. ### Claim 16 (depends on 12) The display device as claimed in claim 12, wherein: the pixels include a red color pixel, a green color pixel, and a blue color pixel, wherein the DC-DC converter is to provide the output voltages to the red color pixel, the green color pixel, and the blue color pixel, respectively, and wherein the output voltages are different from one another. ### Claim 17 A DC-DC converter having an input terminal and a plurality of output terminals, comprising: a plurality of converters to convert a first power voltage at the input terminal to a plurality of second power voltages for output to pixels of a display device through the plurality of output terminals; and a single discharging circuit to discharge the plurality of second power voltages at the plurality of output terminals based on a single discharging control signal, wherein the second power voltages are different from one another and wherein the single discharging control signal is generated when a power mode of the display device switches from a first state to a second state, wherein the single discharging circuit includes: a first switch between a first node directly connected to the converters and a reference terminal, the first switch to turn on based on the single discharging control signal, and a second switch between the input terminal and the first node, the second switch to turn off based on the single discharging control signal, wherein, while the single discharging control signal is applied, the plurality of output terminals are connected to the reference terminal through the first switch of the single discharging circuit such that the plurality of second power voltages at the plurality of output terminals are substantially simultaneously discharged through the first switch of the single discharging circuit.