Switched mode power supply including power supply units and controller

Switched mode power supply assembly comprising:

• a plurality of switched mode power supply units coupled to each other in parallel, each power supply unit comprising:
• an output stage for generating an output signal, the output stage being capable of selectively operating in a first mode wherein the output signal is increasing and operating in a second mode wherein the output signal is decreasing;
• and
• mode switch control means for generating a first mode switch control signal for controlling the output stage to switch from the first operating mode to the second operating mode, and for generating a second mode switch control signal for controlling the output stage to switch from the second operating mode to the first operating mode;
• and
• a control device comprising inputs for receiving the mode switch control signals from all of the plurality power supply units;
• wherein the control device is designed to determine an optimal phase relationship between phases of the mode switch control signals of one power supply unit and phases of the mode switch control signals of a reference power supply unit;
• wherein the control device is designed to compare the phases of the mode switch control signals of said one power supply unit with the phases of the mode switch control signals of said reference power supply unit to determine an actual phase relationship;
• and
• wherein the control device is designed to generate synchronising control signals for at least one of said one power supply unit and said reference power supply unit when the control device finds that the actual phase relationship deviates from the optimal phase relationship, effectively changing the timing of at least one mode switch moment of at least one of said one power supply unit and said reference power supply unit, respectively, such that the deviation between the actual phase relationship and said optimal phase relationship is reduced, in order to ensure interleaved operation of all of the plurality of power supply units.