Switch-mode power supply (SMPS) with auto-tuning using limit-cycle oscillation response evaluation

A switch-mode power supply, comprising:

• energy storage means for storing energy received from an input;
• switching means for transferring energy stored by said storage means to a load;
• control means for controlling said switching means according to a compensated response;
• and
• measurement means for determining a characteristic response of said switch-mode power supply while said stored energy is being transferred to said load, and wherein said control means is responsive to said measurement means to adjust said compensated response, wherein as said characteristic response changes due to variations in said parameters, said compensating response is also changed.

A switch-mode power supply, comprising:

• a magnetic storage element;
• a switching circuit coupled to said magnetic storage element for energizing said magnetic storage element;
• a capacitive storage element coupled to said magnetic storage element, wherein said capacitive storage element is charged by a current transferred from said magnetic storage element to provide an output terminal adapted for coupling to a load;
• a sensing circuit for sensing at least one of a current or a voltage provided at said output terminal;
• a control circuit, for controlling said switching circuit in conformity with a compensating response, wherein said control circuit includes a selectable compensator for providing said compensating response;
• and
• a limit-cycle oscillation measurement circuit for measuring characteristics of a limit-cycle oscillation present in a control variable of said control circuit, whereby characteristics of said switch-mode power supply are obtained, wherein said selectable compensator is selected as an integrator during operation of said limit-cycle oscillation measurement circuit, and wherein said integrator has a gain set such that a crossover frequency of said switch-mode power supply is less than a resonant frequency of said magnetic storage element with said capacitive storage element.