A novel method to operate and control single inductor multiple output switching power converter is presented. The method includes the means for generating one or more synthetic ripple signals and operating the converter at constant switching frequency allowing high frequency operation, maintaining stability in all conditions with minimum cross regulation between the outputs independently on the levels of load present at the outputs. The method further includes means for setting the maximum frequency of multiplexing the energy stored in the inductor between the various outputs reaching the desired compromise between the value of the output capacitors, the switching frequency of the output power devices and the acceptable output voltage ripple.Two different topologies are proposed that can be used for single inductor multiple output buck power converters and for boost power converter allowing the extension to buck-boost configurations as well.