Summary: | 碩士 === 元智大學 === 電機工程學系 === 101 === A fast transient dual-mode DC/DC buck converter with pseudo type-II compensator is presented in this paper. The pseudo-type II compensator is realized with comparator, charge pump and loop filter instead of error amplifier with passive components. Compared with conventional type II compensator, the pseudo-type II compensator decreases the transient time of the buck converter to 1/125 from behavior simulation. The conversion efficiency is improved by adopting pulse width (PWM) modulation in heavy load and pulse frequency modulation (PFM) in light load, respectively. A buck converter with proposed pseudo-type II compensator is simulated in standard 0.18um CMOS process and occupied core area of 0.69mm2. When regulating output voltage of 1V from single 1.8V supply, the transient time of the buck converter is less than 20us during step load of 20mA to 550mA, and vice verse. The conversion efficiency is higher than 93% for load current from 20mA to 550mA.
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