Daisuke Ito, Hiroyuki Asahara, Takuji Kousaka, Tetsushi Ueta, Clock pulse modulation for ripple reduction in buck-converter circuits, Elsevier, Chaos, Solitons & Fractals, in-press, May 2018. Abstract: DC-DC switching converters which are frequently treated as hybrid dynamical systemsexhibit complex behavior due to nonlinear and interrupt characteristics. For synchronousbuck-converters, we propose a method to control chaotic behavior by pulsefrequencymodulation. An input voltage, a duty ratio of PWMs, and so on, affect tothe regulation characteristics of converters directly, but a frequency of PWMs is determinedby the frequency characteristics of the converter and is set as a fixed value. Theproposed chaos-control method suppresses chaotic responses by slightly perturbingthe pulse frequency alone, therefore our method can stabilize unstable periodic orbitswithout influence on the voltage regulation scheme. To simplify the feedback controller,the condition of dimension reduction for the controlling gain vector is derived.The proposed controller acheves the stabilization without a current sensor. Numericalsimulation and circuit implementation demonstrate the validity of this method.