Techniques to Improve the Performance of Wide Operation Range DC-DC Converters

wide operation range;DC-DC converters

Yang, Liyu ; Alex Q. Huang, Committee Chair,Yang, Liyu ; Alex Q. Huang ; Committee Chair

University:North Carolina State University

关键词: wide operation range;    DC-DC converters;   

Others  :  https://repository.lib.ncsu.edu/bitstream/handle/1840.16/6222/etd.pdf?sequence=1&isAllowed=y

美国|英语

来源: null

【 摘 要 】

A lot of DC-DC converters need to work with a wide operation range. It is challengingfor people to achieve a good performance for wide operation range DC-DC convertersbecause of two major reasons. Firstly, when the operation range is wide, the power stageworking condition of the DC-DC converter has a big variation. Secondly, a goodtechnique to improve one part of the performance can be bad for another part of theperformance. Many techniques have been proposed in the literature to improve theperformance of wide operation range DC-DC converters. However, there are still topicswhich require more research, and more novel techniques can be proposed to furtherimprove the performance of wide operation range DC-DC converters. This dissertationmoves forward along this path and makes the following contributions to this researchtopic. (1) A solution is proposed for the large output voltage variation problem when thespread spectrum function is enabled. This practical clock and ramp generation circuit caneliminate this problem, and allows both the input voltage feed-forward function and thespread spectrum function to be easily implemented together in common IC processes. (2)An adaptive external ramp control method is proposed to improve the bandwidth of peakcurrent mode controlled Buck converters with wide operation range. The transientresponse is significantly enhanced. (3) The controller design issues are analyzed and thesolutions are proposed and verified for Buck converters with phase shedding and adaptivevoltage positioning functions. (4) The adaptive device size method is proposed to beapplied to a wide operation range regulated charge pump to improve its light loadefficiency without sacrificing the output ripple.