一种PWM/PFM自动切换的DC-DC芯片  

DC-DC Converter with PWM/PFM Automatic Switching

作　　者：常昌远[1] 姚建楠[1] 谭春玲[1] 邹一照[1] 时龙兴[1] 

机构地区：[1]东南大学集成电路学院,江苏南京210096

出　　处：《应用科学学报》2007年第4期433-436,共4页Journal of Applied Sciences

摘　　要：提出一种可根据负载变化在脉冲宽度调制(pulse width modulation,PWM)和脉冲频率调制(pulse frequency modulation,PFM)两种工作模式间自动切换的降压DC-DC芯片的设计法,推导出临界切换状态下的负载电流值表达式,在此基础上设计了一种PWM/PFM自动切换的DC-DC芯片.该系统在较大的负载变化范围内均具有较高效率.We present an efficient CMOS DC-DC converter with automatic PWM/PFM switching, which can automatically switch between pulse width modulation （PWM） and pulse frequency modulation （PFM） modes according to the load variation. An expression of the load current at the threshold of automatic switching is derived. A simulated system works properly, achieving automatic PWM/PFM switching and high efficiency over a wide ranged of varied load.

关 键 词：PWM/PFM自动切换 切换阈值电流 DC-DC芯片 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]