1.Institute of VLSI Design，IC Design Web-cooperation Research Center of MOE，Hefei University of Technology， Hefei 230601，China； 2.Research Institute of Tsinghua University in Shenzhen，Shenzhen 518057，China
Abstract： Based on the UMC 80 nm process, a charge pump system for AMOLED display drive is designed. In order to ensure that the output voltage ripple of the circuit is less than 10 mV under 8 mA load, this design adopts bilateral symmetric pump circuit structure. In order to maintain the power efficiency above 70% under different output voltages, the pump circuit in this design uses a multi-input power supply structure. In order to maintain the stability of the output voltage, the entire system in this design uses PSM modulation. Hspice simulation of the circuit, in the case of 1 μF pump capacitor and 2.2 μF output capacitor, the load current is 8 mA, the output voltage ripple is 1.2 mV and the power supply efficiency is at least 70% under various output conditions,83.6% peak efficiency.
Key words : charge pump；power management；multiple-input power supply；symmetric pump circuit