A double-stage start-up structure to limit the inrush current used in current-mode charge pump with wide input range,fixed output and multimode operation is presented in this paper.As a widely utilized power source implement,a Li-battery is always used as the power supply for chips.Due to the internal resistance,a potential drop will be generated at the input terminal of the chip with an input current.A false shut down with a low supply voltage will happen if the input current is too large,leading to the degradation of the Li-battery’s service life.To solve this problem,the inrush current is limited by introducing a new start-up state.All of the circuits have been implemented with the NUVOTON 0.6 μm CMOS process.The measurement results show that the inrush current can be limited below 1 A within all input supply ranges,and the power efficiency is higher than the conventional structure.
A double-stage start-up structure to limit the inrush current used in current-mode charge pump with wide input range,fixed output and multimode operation is presented in this paper.As a widely utilized power source implement,a Li-battery is always used as the power supply for chips.Due to the internal resistance,a potential drop will be generated at the input terminal of the chip with an input current.A false shut down with a low supply voltage will happen if the input current is too large,leading to the degradation of the Li-battery's service life.To solve this problem,the inrush current is limited by introducing a new start-up state.All of the circuits have been implemented with the NUVOTON 0.6 μm CMOS process.The measurement results show that the inrush current can be limited below 1 A within all input supply ranges,and the power efficiency is higher than the conventional structure.