| A kind of input ripple current restricted PSM charge pump DC/DC converter is presented in this thesis.The topic stems from a horizontal project cooperated by Power Integrated Technolgy Lab and a domestic company. The typical clock frequency of the charge pump is2.2MHz, supply voltage is3.3V, input voltage is3V-6.5V, two available output voltages, the center value are5.9V and4.1V, output ripple voltage is less than0.6V, input quiescent current is less than0.1mA.0.5um DPTM Mixed Signal process is used.The simulation results with circuit simulation software Hspice prove out that when the voltage of5.7V is applied to the input, the input ripple current of ripple current restricted PSM charge pump decreases by45%comparing with normal PSM charge pump.Before design the specific circuit, the basic operation principle, key parameters and two common control modes (PSM and Linear mode) of2X charge pump DC/DC converter are discussed.Then, a kind of PSM charge pump which combines the idea of Linear mode is proposed. When design the specific circuit, firstly, subblocks of the new charge pump are analyzed, including1X/2X mode selector, output ampler, logic&drivers, clock generator, and over-temperature protector. Typical simulation results are given. Sencondly, the whole charge pump simulation is carried out. The results reveal that the new charge pump has right logic function and work properly, the effect of input rippler current restriction is obvious. At all process corners and in the temperature range of-40℃～125℃, the output ripple voltage, maxium load current and quiescent current of input voltage meet the expectation. |
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