Chip Switching Power Management Ic Design

Single-chip switching power supply management Integrated Circuit (1C) is the latest evolve in the world, it has the virtues of high integration level, most cost effective, lowest component count switcher solution, high performance, forming high efficiency power supply and so on. It has widely application over the world. The object of this paper is to design such a single chip 1C working at high frequency with pulse width modulation (PWM) mode. A lateral double-diffusion MOS with breakdown voltage exceeds 700V is integrated on chip, the maximum output power is about 10W, working frequency is fixed at 100KHz. It has functions to protect itself against over temperature and over current. Cooperating with simple periphery component, a full switch power supply is formed.Circuit designing, key device designing, process designing and part of layout has been finished. Simulation of the whole circuit indicates that the 1C has achieved our expectation including function and parameter target; the key device satisfies breakdown voltage, and the layout design of the LDMOS is given; a process different from conventional epitaxial one is taken to fabricate the power management 1C, it manufacture devices and circuits on a single crystal substrate.During circuit designing, the basic theory of pulse width modulation (PWM) mode is given first. Then the general structure of the 1C is designed based on it's function requirement. Combined with it's work condition, the working course is showed, some key parameters is analyzed in detail such as working frequency, over temperature protection, the way how to low EMI and so on. Every sub-circuit is designed and simulated by author. At last, combined with periphery component, the circuit is simulated, and the result meets the original requirement.An LDMOS is researched as key device, it is fabricated through a single crystal process instead of conventional epitaxial process. The drift region of LDMOS is formed by n-type impurity deep diffusion. Multi termination technology is applied to improve the breakdown voltage, and decrease Ron, that includes RESURF. TheHstructure parameter of LDMOS is obtain through numeric simulation, whose breakdown voltage is 720V and Ron equals 77.8 & -cm.In order to realize the switching power supply management Integrated Circuit, a novel BiCMOS process is introduced, and the conventional epitaxial procedure is abandoned. In this process, low voltage circuit and high voltage power device is integrated on a single crystal substrate. The simplified process flow and layout design rule is given. The author accomplished the layout of LDMOS and part of other low voltage circuit.