The Integrated Oled Display, White Led Driver Circuit Design Study

With the increasing popularity of color LCD displays in cell phones, PDAs, digital cameras, and other portable devices, white LEDs are becoming popular backlighting sources and the drivers to power white LEDs are becoming a new focus in power managing IC. OLED display is an emerging technology that is set to revolutionize displays, offering a number of advantages over LCD. These OLEDs are used in flip-phones, car stereos, MP3 players and various consumer products. Integrated white LED driver with OLED display power supply makes a good prospect for low-power portable application. Switching inductor step-up DC/DC converter is the best resolvent.The research thread and work contents can be summarized as follows:Firstly, the operational principles and sort of white LEDs drivers are introduced. Based on the introduction and the power requirement for OLED display, the whole chip circuit architecture is designed. The architecture adopts a current-mode, step-up DC/DC converter to drive up to white LEDs in series with constant current and to power an OLED display with constant voltage.Secondly, primary sub-block circuits are designed and simulated. The theory of sub-block circuits which include current sensing, PFM comparator, logic and thermal shutdown are analyzed and these sub-block circuits are simulated using HSPICE.Finally, the whole chip function simulation and typical performance characteristics simulation were presented. The simulation results indicate the whole chip circuit has exact functions and meets the demands of applications. In the conclusion of this dissertation, the research value of this circuit was pointed out, but it was suggested that corner simulation and post-layout simulation should be indispensable.This dissertation is a production of circuit principles and simulation practice. Based on the circuit principle analysis, the author simulated the circuit by applying the EDA tool HSPICE. The simulation results indicate that the circuit has achieved the expectation. Furthermore, the circuit principle analysis has been verified.