Passivity-based control of switched-mode power supply for audio amplification systems

The behavior of audio amplifiers imposes a severe load disturbance on power supplies used in amplification systems. Such disturbance can produce an elevation of the ripple magnitude at the voltage rails. Switched-mode power supplies can reduce the increase of the ripple amplitude by employing larger capacitor banks at its output, or using control strategies that decrease its output impedance. This paper proposes the application of a nonlinear passivity-based control technique to a switched-mode power supply, which allows the reduction of the ripple magnitude without the need for bulky reservoir capacitors.