The Design And Research On The Peripheral Driving Circuit Of The Cloured AMOLED Display Based On DVI

In modern information society, the display devices play an important role.CRT (cathode ray tube) display has been existed more than 100 years and isfacing the strong challenge from FPD (flat-panel display). LCD (liquid-crystaldisplay) is the dominant FPD technology. Presently, OLED (organiclight-emitting device) display is recognized that it is the most developmentaldisplay technology of next generation by this field, and it become one of thestudy focus and hotspot in the field of photoelectricity display today. Due to highbrightness, high contrast(100:1), full colour, wide visual angle(largest angle to170°), fast response time, high efficiency, low-voltage driving etc, OLED isregarded as the most strongly challenger of LCD. So the peripheral drivingsystem and driving chip is an important and integrant OLED technology. In ageneral way,OLED display according to type of drive classify twain genera:passive type(passive matrix,namely PM-OLED)and active type(active matrix,namely AM-OLED). A 96×3×128 resolution AMOLED has been designed inthis paper. The display's lead lines include 18 analog voltage data and 14 rowand column control signals. Some power signals are also needed.Many driving IC is designed for the PMOLED currently. There is few ofdriving IC which is designed to drive the AMOLED. And the most of them drivethe displays that display some words, numbers and simple pictures or cartoons.But this can't be satisfied with the expectation to OLED display for people;theyhope they can enjoy the vivid digital video image on the OLED display. Thus theengineer hope to regard the computer that affords digital video image as one ofdata source, make it play synchronously on the OLED display. In order to attainsuch effect, the data transmission from computer to OLED display is veryimportant, DVI interface provides us very large advantage as a new generation ofdigital transmission interface, it has many advantages such as far transmissiondistance, wide data bandwidth and hot plug detection etc. Thus this paperdesigned a chip of driving circuit that can drive the coloured AM-OLED display.The target of this paper is using EDA tools to realize the driving system for the96×3×128 resolution AMOLED display. The system can offer the AMOLEDthe right data and control signals.1. Universal Project of the driving systemTo realize required functions of this study, the project design is shown infigure1. The FPGA controller gets the display data from the DVI interface byway of SRAM. The data are processed in the FPGA. After enlarging its bits andDAC processing, the data are sent to the AMOLED pixels. The FPGA controller,which is droved by a global clock, will generate the row and line driving signals.These signals must be transformed by DC-DC chip and analog switch chip, sotheir wave shape and meet the use of AMOLED.Figure 1 AMOLED driving system project designThe paper's stress is the design of the outer driving system, which includethe digital circuit portion and the analog circuit portion.The digital portion include FPGA controller, DVI data register (SRAM),Configuration device etc.FPGA controller is the core of the whole design, it offer the OLED displaydata and control signals referencing the control strategy. At the same time, FPGAcan do the data processing work. The OLED display data from DVI interface arestored in the DVI data register. Configuration device match the type of FPGA,the configuration data of FPGA are storied in the configuration device. Whenpowered, FPGA read the configuration data from the configuration device andstore it to its SRAM inherent and begin to have the function as designed.The analog portion includes the DAC module and the voltage convertermodule. The DAC chip translate the digital data output by FPGA into analogvoltage data and transfer them to the OLED pixels. And by the effort of DC-DCconverter and analog switch, the required control signals which have the rightshape and voltage are generated.2. Main work of the design(1) Through the study and research to DVI interface and decoding chip, attainthe controlling logic and data signal, and the memory project of data beforebeing sent FPGA.(2) Studying the 96×3×128 resolution AMOLED, analyzed its work principle,built the arithmetic model about all kinds of controlling and data signal thatdisplay needs, confirmed the value of controlling signal and its logic eachother, attained the range of the driving data voltage value based on therequest of AMOLED display processing characteristic.(3) Analyzing the common driving method of the plane display today, based onthe characteristic and configuration of the researching AMOLED, offered themethod of gray-scale generation and the system structure of driving circuit.(4) Designed a kind of peripheral driving circuit integrate chip using the superiorcharacteristic, and attained right simulation result by doing much Verilogsimulation to this chip.(5) Completed the whole peripheral driving circuit system of 96×3×128resolution AMOLED display, offered a kind of feasible project for theperipheral driving technology of AMOLED.In this paper we have studied the AMOLED technology and DVI interface.We have designed a peripheral driving system for the 96×3×128 resolutioncoloured AMOLED display based on DVI interface. We have tested the FPGAcontroller by doing much Verilog simulation. We also have designed andanalyzed the hardware system and have gotten the right control signals anddisplay data stream. And our design has met the needs of the 96×3×128resolution AMOLED display.