Constant-Frequency Peak-Ripple-Based Control of Buck Converter in CCM: Review, Unification, and Duality

Abstract

The operation principles of peak current control, V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> control, and enhanced- V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> control of buck converter in continuous conduction mode are reviewed and compared. By the use of weight factors of inductor current and output voltage, they are unified as constant-frequency peak-ripple-based (CF-PR) analog control. It is revealed that conventional peak current control and V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> control are two boundaries of the unified CF-PR control. The duality items between CF-PR control and constant-frequency valley-ripple-based (CF-VR) control are proposed. As the duality of CF-PR analog control, CF-VR analog control is investigated. Unified CF-PR and CF-VR digital control laws with different modulations and their stabilities are investigated in terms of the duality. Experimental results verify the theory analysis.