| Most mobile equipments to portable battery power, load circuitsare usually controlled by the microprocessor equipment, such asmobile phones, Palmtop computers, and such equipments requirehigher-efficiency power supply and lower output ripple voltage. Hencethe use of power management IC to optimize power management is inneed. Constantly evolving digital technology, the increasing use ofdistributed power structure in terminal equipment, and portableelectronic market is the three major driving for the growth of PowerManagement Technology. The pursuit for greater efficiency, higherreliability, higher power density, smaller chip size and low costsolution has become a common research between industry andacademics.In this thesis, a triple-output DC/DC power management IC isproposed. It combines a high-performance step-up regulator with twolinear-regulator controllers and multiple levels of protection circuitryfor a complete power-supply system, and provides the three regulatedoutput voltages required for active matrix, thin-film transistor liquidcrystal displays (TFT LCDs). Its input operating range is 2.7V~5.5V,in shutdown current is 1ua, and in quiescent current is 1ma. The chipcan also provide a wide range of fault detection mechanisms to ensurethe normal work and avoid chip damage.The boost converter is a current-mode with N-channel powerMOSFET that allow the use of small inductor and ceramic capacitors,it has two working frequency (500kHz/1MHz) to choice. A uniquethree-input Sum-comparator is adopted to replace the traditionalstructure of the error amplifier and a comparator, thus the system is... |
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