Study On Drive Circuit Of OLED

Since 1987,C.W.TANG in Kodak Corp(USA) developed a new kind of organic light-emitting device(OLED) with low drive voltage and high efficiency, OLED has received much attention in the FPD field. With so many excellent virtues, OLED has the potential to dominate the display market in the near future.Firstly, the basic structure, fundamental principle and drive characteristic about the mechanisms of organic electro-luminescence were introduced. Some recent research on the driving circuit design for the PM-OLED was showed. And some kind of driving IC was presented in this thesis too. Then the vision's homochromy PM-OLED customized driver with constant flow source is designed with discrete componment, which work with digital controller to verify the feasibility of driver scheme. Also the performance parameter of this PM-OLED is analysis for the design of integrated driver circuit.The integrated PM-OLED driver circuit is designed with TSMC 0.35um HV 18V HiR DDDMOS technology. The core of the driver circuit is constant flow source module, which supply constant current to pixel of PM-OLED. The module is made up with two parts, one is reference voltage source module which supplies constant voltage, the other is voltage-current covert circuit which converts reference voltage to reference current. The design of reference voltage source module is base on first order temperature compensation of band gap voltage reference, which has a simulation result that the output voltage's Temperature Coefficient is only 16.6ppm/℃. The voltage-current covert circuit is design negative current feedback loop which is made up with a NMOS transistor and a low temperature coefficient resistor. And a extra high gain Operational Amplifier is used for raising transconductance of the NMOS transistor and then for more stability of current. The external resistance was used in the circuit for adapt actual concrete requirement with its adjustability.And then make use of constant current source to design PM-OLED driver circuit row driver circuit and column driver circuit. A new structure of switch-network replace the traditional switch-network. It reduce the impact of the OLED light-emitting unit on circuit switching.Finally, an integrated DC-DC circuit is designed, it meet OLED module's needs. And it is used to provides a different voltages for drive OLED module's digital control and analog drive section...