Design Of Positive And Negative Charge Pump Based On Linear/Burst Control Mode

A Multiple-Output Power Supply for TFT-LCD XD3218 based on linear/burst mode is designed on the basis of the project"Theoretical Research and Design of Key Technique for Deep-submicron Power Management IC and Mixed IC".Firstly, a brief introduction to the power management and the research of TFT-LCD flat panel display power chip are given. Then the structure and operational principle of TFT-LCD are introduced. A system construction of XD3218 is accomplished with respect to the popular control method and operation mode of TFT-LCD driver. Before the detailed description of the sub-block design, the key technologies of DC-DC charge pump in this paper are presented. Finally, some of the whole chip performance characteristics and electrical characteristics are given.Loop stability and power dissipation are the key points of this paper.3x positive charge-pump and -1x negative charge-pump are integrated, which allow the same inner-controlled circuits. This provides a significant simplified design project for the whole-circuit design, especially for back-end design and engineering application. This paper focuses on simplifying design process and lowering down the power dissipation.The design of XD3218 is based on the 0.6μm BCD process. Two charge-pumps are integrated to provide 30V and -7V outputs from 5V inputs respectively. The simulation results show that the performance in application is excellent and can meet the prospective specifications.