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一种PWM/PFM 自动切换的DC-DC芯片

常昌远，姚建楠, 谭春玲，邹一照，时龙兴

  

  1. 东南大学 集成电路学院，江苏 南京 210096
  • 收稿日期:2006-12-01 修回日期:2007-04-03 出版日期:2007-07-30 发布日期:2007-07-30

DC-DC Converter with PWM/PFM Automatic Switching

CHANG Chang-yuan, YAO Jin－nan, TAN Chun-ling, ZOU Yi-zhao, SHI Long-xin   

  1. College of Integrated Circuit, Southeast University, Nanjing 210096, China
  • Received:2006-12-01 Revised:2007-04-03 Online:2007-07-30 Published:2007-07-30

被引次数

6

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。

关键词: PWM, /PFM自动切换, 切换阈值电流, DC-DC芯片

Abstract: 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.

Key words: pulse width modulation (PWM)/pulse frequency modulation (PFM) automatic switching,switching threshold current, DC-DC converter