Adaptive control loop

A duty cycle estimator for determining a duty cycle for controlling a regulated output of an output regulator, the output regulator responsive to the duty cycle for controlling a transfer of energy between an input source and the regulated output, comprising:

• means for error generating to compare the regulated output to an output reference to generate an output error;
• means for accumulating to determine an accumulated error of the output error over a time period of at least N times a switching period of the output regulator, where N is an integer;
• means for generating to generate reference levels;
• and
• means for comparing to compare the accumulated error to the reference levels such that a single zero is generated, and to generate the duty cycle based on the comparing.

A method for determining a duty cycle for controlling a regulated output of an output regulator, the output regulator responsive to the duty cycle for controlling a transfer of energy between an input source and the regulated output, comprising:

• comparing the regulated output to an output reference to generate an output error;
• accumulating the output error over a time period of at least 100 times a switching period of the output regulator to determine an accumulated error;
• generating reference levels;
• and
• comparing the accumulated error to the reference levels such that a single zero is generated, and to generate the duty cycle based on the comparing.