一种新的应用于开关电容DC/DC转换器的补偿电路

A Novel Compensation Circuit Applied for Switched-capacitor DC/DC Converter

采用Chartered 0.35μm CMOS工艺,设计实现了输入电压范围2.7～5.5 V,负载电流高达200 mA的降压式开关电容型DC/DC转换器。为了在整个输入电压和负载电流范围内稳定输出电压,并且提高输出电压精确度,在对开关电容转换器环路建模分析后,提出了一个新的应用于开关电容DC/DC转换器的频率补偿电路。该补偿电路通过在环路中插入零极点并且将原先的主极点推至高频的方法,确保了系统良好的稳定性以及较高的输出电压精确度。流片测试结果表明:系统在整个负载电流范围内,能够保持稳定。负载调整率为0.002 7%,线性调整率为0.376%。

A step-down switched-capacitor DC/DC converter with input voltage range of 2. 7-5.5 V and load current up to 200 mA has been realized in Chartered 0. 35 μm CMOS technology. In order to make the system stable in the whole input voltage range and load current range and improve output voltage accuracy, a novel compensation circuit applied for switched-capacitor DC/DC converter has been proposed after modeling and analyzing the system. The compensation circuit assures the system having better performances of both stability and accuracy by inserting a zero-pole pair in the loop and pushing the original dominate pole to a higher frequency. Tested result shows： the system can work stably in the whole load current range. Load regulation is 0. 002 7%, line regulation is 0. 376%.