Study On The Low-voltage Power Source System In The High-voltage Power Management IC

Recently, Power management IC becomes a very important and active field, due to it can be used for computers, portable equipments, home-devices, industrial control, lighting, space navigation, and military affairs and so on, and its market is very large. With increasing the market scales of all kinds of holistic devices and being more and more important of the problems of the environmental conservation, the problems of power loss and cost is being the hotspot. The wide demands of reducing the loss of the electric products will make the market of power manager IC progress steadily.In the thesis, the basic responsible characteristics of the low-voltage power source system in the power management IC have been studied. Then, the main results are investigated and verified which correspond to both high-voltage current source which is used to transfer a part of the high-voltage main bus power source to the low-voltage power source for the low-voltage control circuit and high-voltage level-shifting circuit which is used to transmit the control signal between two different low-voltage power sources. The results can be used as a criterion for designing the power manager IC.The author's original main work is summarized in Chapter 3, Chapter 4, Chapter 5 and Chapter 6.Firstly, biased on the idea of Professor Chen Xingbi's invention patent"A Semiconductor Device and its Application to Providing Low-Voltage power supply"(Chinese Patent Application No. 200810097388.6), a novel self-generated low-voltage power supply for the gate-driver of high-voltage off-line switching model power supply IC is described. The experimental results have verified that the structure can realize the self-generated function, and be controlled by the low-voltage logic signal. Using this novel power supply structure for the off-line switching model power supply IC can save the cell area, reduce the power consumption of the circuit, make control be easily and supply enough large output voltage for the power supply of the gate driver as well.Secondly, biased on the idea of the Professor Chen Xingbi's inventor patent"A Semiconductor Device and its Application to Providing Low-Voltage power supply"(Chinese Patent Application No. 200810097388.6), a positive and negative power supply for CMOS driver circuit of Electrodeless Fluorescent Lamps is described. The experimental results have verified that the structure can get steady low-voltage power supplies, due to that the low-voltages are controlled by the low-voltage logic signal and be fit for the CMOS driver circuit.Thirdly, a new structure of a lateral n-MOST and a new level-shifting structure with multiply metal rings by divided RESURF technique have been proposed. The device and electrical performances of the structure are analyzed and simulated by MEDICI. In comparison to the level-shifting structure with multiply floating field plates used before, the structure stated here improves the reliability and diminishes the voltage difference between the voltage of the power supply of the high-side gate driver and the voltage of the output terminal of the level-shifting structure, which is also that of the input terminal of the high-side gate driver. The maximal voltage difference of the level-shifting structure in this paper is 30% lower than that used before. Therefore, good voltage isolation and current isolation are obtained. The structure can be used in the level-shifting circuit of various applications.Fourthly, a new quasi-three-dimensional (quasi-3D) numeric simulation method for the high-voltage level-shifting circuit structure is proposed. The performances of 3D structure is analyzed by combining some 2D devices structures, the 2D devices are in two planes perpendicular each to other and to the surface of the semiconductor. Comparing with Davinci, the full 3D device simulation tool, the quasi-3D simulation method can give the results of the potential and current distribution of the 3D high-voltage level-shifting circuit structure with appropriate accuracy and the total CPU time for simulation is reduced significantly. The quasi-3D simulation technique can be used in many cases with merits such as saving computing time, no demand on the high-end computer terminals and easy to operate.