Dynamic AC droop control for DC-DC regulators

A power converter comprising:

• an inductive element having a first terminal and a second terminal adapted to be coupled to a load;
• an output capacitor having a first terminal coupled to the second terminal of the inductive element, and a second terminal coupled to ground;
• and
• a controller comprising:
• a pulse width modulator stage configured to modulate current through the inductive element in response to an error signal;
• a droop signal generation circuit configured to form an alternating current (AC) droop signal in response to controlling a current feedback signal indicative of the current through the inductive element, and to provide a droop signal in response to the AC droop signal;
• and
• a first summing device configured to provide the error signal in response to a difference between a sum of a voltage feedback signal and the droop signal, and a reference voltage.

A method for providing an output voltage across a load by modulating a current through an inductive element, comprising:

• modulating a pulse width of a drive signal provided to a terminal of the inductive element in response to an error signal;
• forming an alternating current (AC) droop signal in response to a current feedback signal indicative of the current through the inductive element, the forming comprising controlling the forming;
• forming a droop signal in response to the AC droop signal;
• and
• providing the error signal in response to a difference between a sum of a voltage feedback signal and the droop signal, and a reference voltage.

A controller for a power converter for providing an output voltage across a load by modulating a current through an inductive element, the controller comprising:

• means for modulating a pulse width of a drive signal provided to a terminal of the inductive element in response to an error signal;
• means for forming an alternating current (AC) droop signal in response to a current feedback signal indicative of the current through the inductive element, the means for forming the AC droop signal comprising means for controlling the forming;
• means for forming a droop signal in response to the AC droop signal;
• and
• means for providing the error signal in response to a difference between a sum of a voltage feedback signal and the droop signal, and a reference voltage.