The longest off time duration highest efficiency and highestouput ripple voltage are featured for burst mode detecting output votagevia hysteresis comparator. The least efficiency and least ouput ripplevoltage is featured for force continuous mode with positive and negativecurrent through the inductor. ...
ApplicationNote王信雄AN009–Jul2014AN009©2014RichtekTechnologyCorporation1Buck转换器的电流纹波系数CurrentRippleFactorofaBuckConverter摘要电感和电容在Buck转换器中构成低通滤波器,此LC滤波器的转折频率总是设计得较低以便滤除开关纹波。常用的设计规则是,电感电流纹波被设计成电感平均电流的30%左右。本文引入表达电感...
outputvotageviahysteresiscomparator.Theleastefficiencyandleastouputripplevoltageisfeaturedforforcecontinuousmodewithpositiveandnegativecurrentthroughtheinductor.Theefficiencyandouputripplevoltageofpulseskipmodewithskippingsomeswithchingpulseisbetweenthatoftwomodesabove.Themethodstocalculatetheinductanceinputcapitanceandoutput...
In this application note, a theoretical derivation of ripple current to average current ratio, also called ripple factor, is introduced to get inductor size equation, which is helpful for capacitor design as well as the total converter design.
After that, considering the reverse slip output inductor current problem which makes the output current ripple larg 7、e, I present another method which can avoid the problem. Key words:Buck converter, soft switching, saber simulation目 录摘 要IABSTRACTII1 绪论11.1 研究背景11.2 研究的目的及意义...
图7 电感电流脉动量标幺曲线 Fig.7 Scal-unit curves of the ripple of inductor current图8 电感电流标幺化均值曲线 Fig.8 Scal-unit curves of the average value of inductor current相较于两模式控制策略,该控制方式能够解决在输入输出电压接近时,变换器在Buck模式和Boost模式下频繁切换影响系统稳定运行的问题...
Fig.4 The relationship between input inductor peak current and output current and gain 3.2 CCM与DCM临界条件及临界电感 变换器的工作模式,通过确定临界电感的值进行明确划分,得到临界电感的确切取值,有利于电路的进一步优化与设计。 当开关管关断时,L3两端的电压为输出电压,因此,电感电流变化量∆iL3可以表示为...
8 Waveforms of inductor current ripple 3.2 两模式双沿调制方式的优点 将式(12)和d =0 分别代入式(11),可推导出两 如果 2 只开关管同时开通和关断,则四管 2 模式双沿调制方式下电感电流有效值: Buck-Boost变换器工作在Buck-Boost模式,称其为 ⎧ U 2 (U −U )U 2 单模式调制,4 只开关管均...
Boost regulators are more difficult to design than buck regulators, regardless of whether we control the output voltage or the output current. The average inductor current in a continuous conduction mode (CCM) boost converter is equal to the load current (LED current) multiplied by 1/(1 - D)...
2 全面认识开关型电源中的BUCK-BOOST功率级 ZHCA041–1999年3月–2002年11月修订 2 Buck-Boost Stage Steady-State Analysis A power stage can operate in continuous or discontinuous inductor current mode. Continuous inductor current mode is characterized by current flowing continuously in the www.itni.dco...