# US 11,908,422 B2 · Digital driving circuit, digital-analog converter having decoders with different turn on/off state, and display device thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,908,422 B2 - Document ID: US11908422B2 - Status: Granted - Kind: B2 - Application number: 17/986,675 - Filed: 2022-11-14 - Published: 2023-03-09 - Granted: 2024-02-20 - Earliest claimed: 2020-07-10 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Hyung Gun Ma; Oh Jo Kwon; Ji Woong Kim; Jun Yong Song; Seong Joo Lee; Sang Hyun Heo - Web page: https://patentgrep.com/patent/US11908422B2 ## CPC - G09G 3/3266: Details of drivers for scan electrodes - G09G 3/3275: Details of drivers for data electrodes - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - H03M 1/66: Digital/analogue converters ({H03M1/001 – } H03M1/10 take precedence) - G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED] - G09G 2310/0259: with use of an analog or digital ramp generator in the column driver or in the pixel circuit - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2310/0291: Details of output amplifiers or buffers arranged for use in a driving circuit - G09G 2310/0297: Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns - G09G 2310/066: Waveforms comprising a gently increasing or decreasing portion, e.g. ramp - G09G 2330/021: Power management, e.g. power saving - G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD - H03M 1/76: using switching tree - 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) - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) ## Abstract A digital-analog converter of the disclosure converts digital image data to generate analog data signals. The digital-analog converter includes a voltage divider which generates a plurality of gamma reference voltages based on a first reference voltage and a second reference voltage; a global ramp including a plurality of gamma decoders which generates a plurality of global gamma voltages based on the gamma reference voltages; a decoder which selects one of the global gamma voltages according to the digital image data to generate the analog data signals; and a ramp controller which turns off at least some of the gamma decoders based on the digital image data. ## Claims ### Claim 1 A data driving circuit, comprising: a digital-analog converter to receive image data of a digital format, to receive a reference voltage to generate a plurality of gamma reference voltages based on the reference voltage, and to convert the image data of the digital format into analog data signals of an analog format based on a portion of the plurality of gamma reference voltages, wherein the digital-analog converter comprises: a plurality of gamma decoders to generate a plurality of global gamma reference voltages, each of the plurality of global gamma reference voltages being generated based on at least some of the plurality of gamma reference voltages; and a decoder to output one of the plurality of global gamma reference voltages corresponding to the image data of the digital format to generate the analog data signals, and wherein at least some of the plurality of gamma decoders are turned off while remaining gamma decoders among the plurality of gamma decoders except for the at least some of the plurality of gamma decoders maintain a turn-on state, wherein the at least some of the plurality of gamma decoders are turned off based on the image data of the digital format. ### Claim 2 (depends on 1) The data driving circuit according to claim 1, further comprising a ramp controller to generate a ramp control signal by comparing most significant bits of the image data of the digital format, wherein the at least some of the plurality of gamma decoders are turned off based on the ramp control signal. ### Claim 3 (depends on 1) The data driving circuit according to claim 1, further comprising a ramp controller to generate a ramp control signal by comparing most significant bits of the image data of the digital format, and comparing second most significant bits of the image data of the digital format, wherein the at least some of the plurality of gamma decoders are turned off based on the ramp control signal. ### Claim 4 (depends on 1) The data driving circuit according to claim 1, further comprising a voltage divider to generate the plurality of gamma reference voltages based on the reference voltage. ### Claim 5 (depends on 1) The data driving circuit according to claim 1, further comprising a global ramp including the plurality of gamma decoders. ### Claim 6 A method of driving a data driving circuit, the method comprising: obtaining image data of a digital format; generating a plurality of gamma reference voltages based on a reference voltage by a plurality of gamma decoders included in the data driving circuit; generating a plurality of global gamma reference voltages, wherein each of the plurality of global gamma reference voltages is generated based on a portion of the plurality of gamma reference voltages; outputting one of the plurality of global gamma reference voltages corresponding to the image data of the digital format; converting the image data of the digital format into analog data signals based on the one of the plurality of global gamma reference voltages; and turning off at least some of the plurality of gamma decoders while maintaining remaining gamma decoders among the plurality of gamma decoders except for the at least some of the plurality of gamma decoders in a turn-on state, wherein the at least some of the plurality of gamma decoders are turned off based on the image data of the digital format. ### Claim 7 A method of driving a data driving circuit, the method comprising: obtaining image data of a digital format; generating a plurality of gamma reference voltages based on a reference voltage by a plurality of gamma decoders included in the data driving circuit generating a plurality of global gamma reference voltages, wherein each of the plurality of global gamma reference voltages is generated based on a portion of the plurality of gamma reference voltages; outputting one of the plurality of global gamma reference voltages corresponding to the image data of the digital format converting the image data of the digital format into analog data signals based on the one of the plurality of global gamma reference voltages; turning off at least some of the plurality of gamma decoders while maintaining remaining gamma decoders among the plurality of gamma decoders except for the at least some of the plurality of gamma decoders in a turn-on state; and comparing most significant bits of the image data of the digital format. ### Claim 8 (depends on 7) The method of claim 7, wherein a ramp control signal is generated by comparing the most significant bits of the image data of the digital format. ### Claim 9 (depends on 7) The method of claim 7, further comprising comparing second most significant bits of the image data of the digital format. ### Claim 10 (depends on 9) The method of claim 9, wherein a ramp control signal is generated by comparing the most significant bits of the image data of the digital format and by comparing the second most significant bits of the image data of the digital format.