| Power management chips are widely used in portable electronic products with battery power supply. The development trenches of the power management chip require smaller size, lower power consumption and higher power convert efficiency. The internal modulate transistor of DC-DC converter operating at high frequency with small equivalent impedance and litter power consumption, has the power convert efficiency higher than90%. Therefore, it is widely used in mobile phone, digital camera, PDAs, etc. and became the developing direction of steady voltage supply. This work is mainly to design high efficiency, high frequency integrated DC-DC switching power supply considering both economy and practical factors.In this thesis, a new type of current mode pulse-width-modulation (PWM) DC-DC single chip power supply is designed for CSMC0.5um2P3M mixed signal CMOS process. Comparing to the traditional single boost or buck mode, our designed converter can work in both boost mode and buck mode through adjusting the input voltage to set four power MOS switches in different states. This converter efficiently extends the range of the input voltage, and enhances the power conversion efficiency. The maximum output current can reach1A.This thesis introduced the basic principle and control techniques of DC-DC converter, proposed the global system architecture upon the design requirements, systematically studied six essential sub-block circuits, which including band-gap reference, under voltage lock-out, oscillator, error amplifier and comparator circuit. The function of the sub-circuits and the whole chip circuit are simulated by cadence spectre software based on the theoretical analysis and circuit design. The simulation results indicate that the chip has achieved the design requirements, and validated the theory analysis and design. |
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