Based On The Voltage-mode Pfm Dc-dc Boost Converter Control Research And Design

Along with the portable equipments are used widely, the power managementindustry are encountering good opportunity and enormous challenge. The marketrequirement is attracting more and more integrated circuits design corporations enteringinto the power management industry, and the competition is focused on low cost andhigh performance. A voltage mode and PFM controlled step-up DC-DC converter withthe controller chip powered by the output is designed in this thesis, and the controllerchip can boost under low input voltage condition, and it is applicable to many portableequipments such as mobile phones, PDA, and digital cameras. The chip takes the 0.5/μmand 5V standard CMOS process. The control policy is voltage control mode (VCM)and Pulse Frequency Modulation (PFM). The input voltage range is from 0.9V to 2.0V,and the output voltage is 3V. Shut-down mode is one of the features, and then thestandby current is no more than 0.5μA. The temperature range is -30℃～80℃.The topology of the step-up DC-DC converters and its basic principle is firstanalyzed in this thesis. Then an analysis and comparison between the PWM scheme andPFM scheme, and between the voltage control mode and current control mode are maderespectively. Next, The whole chip and its sub-block circuits are well-designed based onthe designed function. Lastly, the author pays more attention to the analysis and designon the following sub-circuits: Voltage Reference, Comparator, Oscillator, and OverCurrent Protect.After completing the principle analysis and circuit design, the sub-circuits andwhole chip circuit are verified with the EDA tools HSPICE. The simulation results areall in accordance with the theory analysis, some even better than the theoreticalspecification.