# US 10,504,474 B2 · Data driver and display device with the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,504,474 B2 - Document ID: US10504474B2 - Status: Granted - Kind: B2 - Application number: 16/373,522 - Filed: 2019-04-02 - Published: 2019-07-25 - Granted: 2019-12-10 - Earliest claimed: 2015-07-31 - Assignees: Samsung Display Co., Ltd.; Sogang University Research Foundation - Applicants: Samsung Display Co., Ltd.; Sogang University Research Foundation - Inventors: Moon Sang Hwang; Weon Jun Choe; Jun Sang Park; Tai Ji An; Seung Hoon Lee - Web page: https://patentgrep.com/patent/US10504474B2 ## CPC - G09G 3/3688: {suitable for active matrices only} - G09G 3/3696: {Generation of voltages supplied to electrode drivers} - G09G 2310/0291: Details of output amplifiers or buffers arranged for use in a driving circuit - 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) ## Abstract A data driver includes a digital to analog converter configured to receive a reference gray voltage and image data, and configured to generate gray voltages corresponding to the image data, and an output buffer including a plurality of buffer circuits connected to an output terminal of the digital to analog converter, and configured to selectively receive one of the gray voltages. ## Claims ### Claim 1 A data driver comprising: a digital to analog converter configured to receive a reference gray voltage and image data, and configured to generate gray voltages corresponding to the image data; and an output buffer comprising a plurality of buffer circuits connected to an output terminal of the digital to analog converter, and configured to selectively receive one of the gray voltages, wherein each of the buffer circuits comprises: a switch connected to the output terminal of the digital to analog converter, and configured to sequentially transmit a corresponding one of the gray voltages; a unit gain buffer; and a voltage stabilizer connected between an output terminal of the switch and a non-inverting input terminal of the unit gain buffer, and configured to stabilize an input voltage of the unit gain buffer. ### Claim 2 (depends on 1) The data driver of claim 1, wherein the digital to analog converter is further configured to sequentially output the gray voltages, and wherein each of the buffer circuits is configured to selectively receive the corresponding one of the gray voltages. ### Claim 3 (depends on 2) The data driver of claim 2, wherein the unit gain buffer is configured to transmit the corresponding one of the gray voltages from the switch to a data line. ### Claim 4 (depends on 1) The data driver of claim 1, wherein the output terminal of the switch and the non-inverting input terminal of the unit gain buffer are electrically connected, and wherein the voltage stabilizer comprises a capacitor connected between the output terminal of the switch and ground. ### Claim 5 (depends on 1) The data driver of claim 1, wherein the voltage stabilizer comprises a source follower connected between the output terminal of the switch and the non-inverting input terminal of the unit gain buffer. ### Claim 6 (depends on 1) The data driver of claim 1, wherein the unit gain buffer comprises a folded cascode amplifier. ### Claim 7 (depends on 1) The data driver of claim 1, wherein the unit gain buffer comprises a class AB amplifier. ### Claim 8 (depends on 1) The data driver of claim 1, wherein the switch comprises a CMOS transistor. ### Claim 9 (depends on 1) The data driver of claim 1, wherein the switches of the buffer circuits are configured to be sequentially turned on over time, and are configured to sequentially receive the gray voltages from the digital to analog converter one at a time. ### Claim 10 (depends on 1) The data driver of claim 1, wherein the buffer circuits are connected to the output terminal of the digital to analog converter to concurrently receive a same output signal from the digital to analog converter. ### Claim 11 A display device comprising: a display panel comprising a plurality of pixels at respective crossing regions of a plurality of data lines and a plurality of gate lines; a gate driver connected to the plurality of gate lines; a data driver connected to the plurality of data lines; and a signal controller configured to control operations of the gate driver and the data driver, wherein the data driver comprises: a digital to analog converter configured to receive a plurality of reference gray voltages and image data, and configured to generate gray voltages corresponding to the image data; and an output buffer comprising a plurality of buffer circuits connected to an output terminal of the digital to analog converter, and configured to selectively receive one of the gray voltages, and wherein each of the buffer circuits comprises: a switch connected to the output terminal of the digital to analog converter, and configured to sequentially transmit a corresponding one of the gray voltages; a unit gain buffer; and a voltage stabilizer connected between an output terminal of the switch and a non-inverting input terminal of the unit gain buffer, and configured to stabilize an input voltage of the unit gain buffer. ### Claim 12 (depends on 11) The display device of claim 11, wherein the unit gain buffer is configured to transmit the corresponding one of the gray voltages from the switch to a data line. ### Claim 13 (depends on 12) The display device of claim 12, wherein the output terminal of the switch and the non-inverting input terminal of the unit gain buffer are electrically connected, and wherein the voltage stabilizer is connected between the output terminal of the switch and ground. ### Claim 14 (depends on 11) The display device of claim 11, wherein the voltage stabilizer comprises a source follower connected between the output terminal of the switch and the non-inverting input terminal of the unit gain buffer. ### Claim 15 (depends on 11) The display device of claim 11, further comprising a gray voltage generator configured to generate the plurality of reference gray voltages, and configured to transmit the plurality of reference gray voltages to the data driver. ### Claim 16 (depends on 11) The display device of claim 11, wherein the buffer circuits are connected to the output terminal of the digital to analog converter to concurrently receive a same output signal from the digital to analog converter.