A wide load range,multi-mode synchronous buck DC-DC converter with a dynamic mode controller and adaptive slope compensation  

作　　者：张春红 杨海钢 史传进 

机构地区：[1]Institute of Electronics,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Silicon System Research Laboratory,Department of Electronic Engineering,210EE/CES Building,Box 352500,University of Washington Seattle

出　　处：《Journal of Semiconductors》2013年第6期102-109,共8页半导体学报（英文版）

基　　金：supported by the Major National Scientific Research Plan,China(No.201 1CB933202);the CAS/SAFEA International Partnership Program for Creative Research Teams

摘　　要：A synchronous buck DC-DC converter with an adaptive multi-mode controller is proposed.In order to achieve high efficiency over its entire load range,pulse-width modulation（PWM）,pulse-skip modulation（PSM） and pulse-frequency modulation（PFM） modes were integrated in the proposed DC-DC converter.With a highly accurate current sensor and a dynamic mode controller on chip,the converter can dynamically change among PWM, PSM and PFM control according to the load requirements.In addition,to avoid power device damage caused by inrush current at the start up state,a soft-start circuit is presented to suppress the inrush current.Furthermore,an adaptive slope compensation（SC） technique is proposed to stabilize the current programmed PWM controller for duty cycle passes over 50%,and improve the degraded load capability due to traditional slope compensation.The buck converter chip was simulated and manufactured under a 0.35μm standard CMOS process.Experimental results show that the chip can achieve 79%to 91%efficiency over the load range of 0.1 to 1000 mA.A synchronous buck DC-DC converter with an adaptive multi-mode controller is proposed.In order to achieve high efficiency over its entire load range,pulse-width modulation（PWM）,pulse-skip modulation（PSM） and pulse-frequency modulation（PFM） modes were integrated in the proposed DC-DC converter.With a highly accurate current sensor and a dynamic mode controller on chip,the converter can dynamically change among PWM, PSM and PFM control according to the load requirements.In addition,to avoid power device damage caused by inrush current at the start up state,a soft-start circuit is presented to suppress the inrush current.Furthermore,an adaptive slope compensation（SC） technique is proposed to stabilize the current programmed PWM controller for duty cycle passes over 50%,and improve the degraded load capability due to traditional slope compensation.The buck converter chip was simulated and manufactured under a 0.35μm standard CMOS process.Experimental results show that the chip can achieve 79%to 91%efficiency over the load range of 0.1 to 1000 mA.

关 键 词：DC-DC MULTI-MODE peak current mode slope compensation soft-start 

分 类 号：TM44[电气工程—电器] TN402[电子电信—微电子学与固体电子学]