一种高电压转换倍率的电荷泵设计

Design on a Charge Pump with High Voltage Conversion Rate

为解决传统的电荷泵在工作中存在的阈值压降问题和传输管的体效应问题,提出一种高电压转换倍率电荷泵电路。电路采用SMIC 0.18μm CMOS工艺制作,在传统交叉耦合电荷泵结构的基础上,通过增加衬底的动态偏置电路动态地调节传输管的衬底电位,使衬底电位与源极电位保持一致,以此消除体效应的影响,提高电荷泵电路的输出电压和电压转换倍率。按照设计方案进行仿真实验,结果表明改进后的电荷泵在0.8~1.8V电源电压下,电压转换倍率都能保持在98.5%以上。

In order to solve the threshold voltage drop problem and the body effect problem of the transmission tube existing in the traditional charge pump,a charge pump circuit with high voltage conversion ratio is proposed.The circuit is fabricated using SMIC 0.18μm CMOS process.Based on the traditional cross-coupled charge pump structure,the substrate potential of the transmission tube is dynamically adjusted by adding a dynamic bias circuit of the substrate,so that the substrate potential is consistent with the source potential,thereby eliminating the influence of body effect and improving the output voltage and voltage conversion ratio of the charge pump circuit.According to the design scheme,the simulation experiment shows that the voltage conversion ratio of the improved charge pump can be kept above 98.5%under the power supply voltage of 0.8~1.8V.