摘要：A power management unit （PMU） chip supplying dual panel supply voltage, which has a low electro-magnetic interference （EMI） characteristic and is favorable for miniaturization, is designed. A two-phase charge pump circuit using external pumping capacitor increases its pumping current and works out the charge-loss problem by using bulk-potential biasing circuit. A low-power start-up circuit is also proposed to reduce the power consumption of the band-gap reference voltage generator. And the ring oscillator used in the ELvSS power circuit is designed with logic devices by supplying the logic power supply to reduce the layout area. the PMU chip is designed with MagnaChip＇s 0.25 μ high-voltage process. the driving currents of ELvDD and ELvSS are more than 50 mA when a SPICE simulation is done.