Burst-mode switching voltage regulator with ESR compensation

A burst-mode switching voltage regulator comprising:

• a voltage regulator circuit having an output coupled to an output capacitor, wherein the output capacitor has a low equivalent series resistance, the voltage regulator circuit being configured to provide an output voltage, the voltage regulator circuit comprising:
• a power switch coupled to an input power source, the power switch to selectively complete a current path from the input power source through an energy storage device to provide an output current at a specified voltage level;
• a current sense circuit coupled to the power switch, the current sense circuit being configured to detect a current flowing through the power switch and generate a current signal consisting essentially of an AC component thereof;
• a feedback compensator circuit coupled to the current sense circuit and to a feedback control signal line, the feedback compensator circuit being configured to generate a signal based upon the current signal and a voltage feedback control signal that is a direct measurement of the output voltage and is to be used to control the state of the power switch;
• and the burst-mode switching voltage regulator further comprises
• a resistor-divider network coupled in parallel to the output capacitor, the resistor-divider network to provide the voltage feedback control signal.

A method for regulating a voltage in a burst-mode switching voltage regulator, the method comprising:

• sensing a current feedback signal based upon an output current consisting essentially of an AC component therof;
• sensing a voltage feedback signal that is a direct measurement of an output voltage;
• deriving a control signal based upon the current feedback signal and the voltage feedback signal;
• and
• using the control signal to control the state of a switch regulating current flow in the burst-mode switching voltage regulator.