摘要
提出一种适用于电流模式降压型DC-DC转换器的负载自适应方案(LAM).该方案在宽负载范围内具有高效率.采用误差信号与负载自适应的门限做比较,判定转换器工作模式,根据负载电流的大小使开关工作在PWM模式或轻载模式.在轻载模式下,通过循环开启或者关闭振荡器来降低转换器的开关频率,减少开关损耗和静态功耗.对负载自适应阈值,电感峰值电流和负载电流之间的关系进行了分析和推导.采用0.5μm BCD工艺,仿真结果显示在输入电压12V,输出电压3.3V,负载较轻时,转换器进入LAM模式,转换效率大大高于同样负载下的PWM模式,特别是在ILoad=10mA时,PWM模式的转换效率只有45.6%,而LAM模式的转换效率棕80.1%.
A current mode buck DC-DC converter with using a load adaptive method (LAM ) to keep high efficiency within wide load current range are presented in this paper .The converter used error signal and a load adaptive threshold to flexible switch in pulse width modulation (PWM ) mode and skip mode according to the load current .In skip mode ,the converter can reduce switching loss and quiescent consumption .Through analysis and derivation ,the relations between load adaptive threshold ,inductance peak current and load current were inferred .Simulation results implemented in 0 .5 μm BCD process shows that ,under the condition of 12 V input and 3 .3 V output ,When the load is light ,the converter enters LAM mode ,the efficiency is much higher than the same load in PWM mode , especially in ILoad= 10 mA ,the efficiency of PWM mode is only 45 .6% ,but in LAM mode the efficiency reach 80 . 1% .
出处
《微电子学与计算机》
CSCD
北大核心
2014年第10期138-142,共5页
Microelectronics & Computer
基金
国家自然科学基金项目(61271090)
国家高技术研究发展计划("八六三"计划)重大项目(2012AA012305)
关键词
负载自适应
降压型
轻负载
峰值电流模式
宽负载
load adaptive
buck
light load
high efficiency
inductance peak current
Wide load
