开关电源的多模式控制策略及实现  

Strategy and implementation of multi-mode control in switch-mode power supply

作　　者：姜伟[1] 赵野[1] 

机构地区：[1]中国科学院微电子研究所,北京100029

出　　处：《浙江大学学报（工学版）》2014年第9期1580-1585,共6页Journal of Zhejiang University：Engineering Science

基　　金：广东省中国科学院全面战略合作资助项目(2011A090100010);国家自然科学基金资助项目(61006058)

摘　　要：为了减小开关电源的待机功耗和提高系统的工作效率,提出一种多模式调制控制策略并予以实现.该策略主要包括3种调制模式:准谐振调制方式、脉冲频率调制方式和跳周期调制方式.准谐振调制方式在重载时效率较高,但随着负载的降低其开关频率上升,从而使得开关损耗变大;脉冲频率调制方式在中载时效率较高,能够根据负载的变化调节开关频率,避免开关损耗过大造成效率降低;跳周期调制方式在轻载时效率较高,能够在一定时间内使开关管不动作,进一步降低开关损耗.采用700VBCD工艺设计一款集成3种调制模式的开关电源芯片,并针对不同的负载进行优化,比起传统脉冲宽度调制方式,在整个负载范围内的系统效率提高,待机功耗降低.基于该芯片开发的开关电源系统(12V/1A),能够根据负载轻重自适应地在3种调制方式之间平稳切换,其实测待机功耗低于90mW,平均效率大于84%,均优于传统脉冲宽度调制模式的开关电源,可完全满足V2.0版本的"能源之星"标准的要求.A multi-mode control strategy is presented and implemented to reduce the standby power and in- crease the efficiency of the switch-mode power supply （SMPS）. Three different modes： quasi-resonant （QR） mode, pulse frequency modulation （PFM）mode and pulse skipping modulation （PSM）mode are ap- plied in the strategy. In QR mode, the efficiency is high when the load is heavy, but the power loss of the switch is larger as the load is heavier. In PFM mode, the efficiency is high when the load is medium, and the switch frequency varies according to different loads to avoid excessive power loss. The efficiency in PSM mode is high when the load is light, and switch turns off for a set amount of time to further decrease the power loss. A chip was designed and fabricated on 700 V BCD technology and the optimization was achieved according to different loads. Compared to the conventional pulse width modulation （PWM）mode, the novel strategy can greatly reduce the no-load power consumption and increase the average efficiency in the full range of variable load. To verify the performance of the proposed strategy, a 12 W （12 V/1 A） la- boratory prototype was built. The experimental results show that the SMPS can work adaptively in differ- ent modes according to variable loads. The measured average efficiency is over 84% and the standby power consumption is less than 90 mW, which both fully meet the requirements of version 2.0 Energy Star speci- fication.

关 键 词：待机功耗 多模式 准谐振调制 能源之星 

分 类 号：TN432[电子电信—微电子学与固体电子学]