Research On Common Mode-Differential Mode Controlled Single Inductor-Dual Output Buck Converter

Single-inductor dual-output(SIDO)Buck converters use only one inductor to achieve dual DC voltage output.It has the characteristics of low production cost,small size and high conversion efficiency.With broad application prospects,it can be used as a power supply topology for portable mobile devices and has become a research hotspot at home and abroad in recent years.Take common-mode-differential-mode voltage control SIDO Buck converter as the research object.In-depth analysis of the converter’s working process in fully inductive power supply mode(CISM),incomplete inductive power supply mode(IISM)and discontinuous conduction mode(DCM).The output voltage and critical inductance analytical formulas of these three working modes are obtained,and the output ripple voltage models of the three working modes are established at the same time,and the characteristics of the output ripple voltage are analyzed and summarized.In order to obtain the control parameter range of the common-mode-differential-mode voltage control SIDO Buck converter,the state-space averaging method is used to establish the mathematical model of the common-mode-differential-mode voltage control SIDO Buck converter,and according to the state-space average model of the converter,Combining the Jacobian matrix and the Rouss-Herviz criterion,the stability is analyzed,and the stable range of the closed-loop system control parameters is obtained,which lays the theoretical foundation for the controller parameter design.In order to obtain the parameter design method of the inductance and capacitance of the common mode-differential mode voltage control SIDO Buck converter,the critical inductance,inductor ripple current and output ripple voltage of the converter are deeply analyzed.Through discussion within a certain dynamic range of input voltage and load resistance,the maximum analytical formulas of inductor ripple current and output ripple voltage are obtained.At the same time,the analytical formulas for the inductance values of the converter working in CCM and DCM are given.And taking working mode,inductor ripple current and output ripple voltage as constraints,the parameter design method of converter inductance and capacitance is obtained.The value range of the control parameter is obtained through the inductance and capacitance parameters obtained and combined with the stability conditions.The parameter design method is reasonable through the final experimental platform built.