摘要
提出了一种针对便携式电子产品的高效单片开关DC/DC转换器.采用固定关断时间PWM控制方式代替传统的固定频率PWM控制方式,转换器的开关频率和开关电流损耗随输入电压减小而降低,弱化了转换效率随电池电压下降而降低的趋势;除一般PWM/PFM供电模式外,该转换器增设了LDO供电模式以降低转换器的最小输入电压,提高了电池使用效率;另外,该转换器采用既能消除开关管与同步整流管瞬通电流损耗、又能消除其驱动缓冲级瞬通电流损耗的"嵌套"死区缓冲器.仿真结果表明,该转换器转换效率高达95%.转换芯片以0.5μm2P3M Mixed Signal CMOS工艺流片,实测效率达91%.
A monolithic high-efficiency switch DC / DC converter for portable electronics is presented.Utilizing the pulse width modulation（PWM） control technology based on fixed off-time instead of that based on fixed-frequency,both the switch frequency and the switch current loss of the proposed converter decrease with battery voltage dropping,which weakens the trend of lower conversion efficiency with the battery voltage dropping in the later technology.As well as the traditional PWM/PFM mode,the low dropout regulator（LDO） mode is designed to lower the minimum input voltage;and so the battery application efficiency is improved.In addition,the nested dead-time buffer is used in the proposed convertor,which not only eliminates the instantaneous-through current loss existing between the switch transistor and synchronous rectifier transistor but also the instantaneous-through current loss presented at their driving buffer.The simulation results show that conversion efficiency of the proposed converter is up to 95%.The chip is fabricated on 0.5μm 2P3M mixed signal CMOS process.The measured efficiency is as high as 91%.
出处
《武汉大学学报（工学版）》
CAS
CSCD
北大核心
2012年第5期648-653,共6页
Engineering Journal of Wuhan University
基金
"十二五"预研基金项目
关键词
DC/DC转换器
转换效率
脉冲宽度调制
脉冲频率调制
低压差稳压器
同步整流
嵌套死区缓冲器
DC/DC converter
conversion efficiency
pulse width modulation（PWM）
pulse frequency modulation（PFM）
low dropout regulator（LDO）
synchronous rectifier
nested dead-time buffer
