摘要
为了提高单电感双输出升/降压型直流-直流转换器在轻载下的效率,设计实现了适用于不同转换条件的非连续导通模式（DCM）功能和脉冲频率调制（PFM）控制。前者降低了电感电流的均方根值,减少了导通损耗;后者降低了开关频率,减少了开关损耗。详细分析了在PFM控制下转换器的驱动能力、电感电流纹波和输出电压纹波之间相互制约的关系,并采取了一种可以由两路任意升/降压输出灵活复用的自适应导通时间控制方法。经0.25μm 2P4M CMOS混合信号工艺流片验证,测试结果显示DCM和PFM时序与设计方案吻合,各种转换条件下输出电压纹波在40~70 mV。通过比较发现,对轻载效率的提升可以达到30%以上。
Discontinuous conduction mode（DCM） function and pulse-frequency modulation（PFM） control available in both buck and boost conversion are realized to improve the light-load efficiency of a single-inductor dual-output buck-boost DC-DC converter.For DCM,the root-mean-square magnitude of inductor current decreases,reducing the conduction loss.While under PFM control,switching frequency decreases,reducing the switching loss.Based on the analysis of the tradeoff among driving capability,inductor current ripple and output voltage ripple,a more flexible adaptive on time PFM control is realized,which can be shared by both outputs for either buck or boost conversion.The chip is implemented on a 0.25 μm 2P4M CMOS mixed-signal technology.The measurement results show that the timing of DCM and PFM are correct.For various power conversions,the output ripples are 40~70 mV.Compared with measured data of PFM control applying DCM or not,this work enhances light-load conversion efficiency evidently.
出处
《固体电子学研究与进展》
CAS
CSCD
北大核心
2011年第5期510-516,共7页
Research & Progress of SSE
基金
Dialog公司资助项目
关键词
单电感双输出
升/降压型转换器
非连续导通模式
脉冲频率调制
自适应导通时间控制
single-inductor dual-output（SIDO）
buck-boost converter
discontinuous conduction mode（DCM）
pulse-frequency modulation（PFM）
adaptive on time control
