A Configurable DC-DC Ripple Attenuator Module With an Active Ripple Cancellation Technique

The active ripple canceller used in multiphase buck converters (MBCs) always guarantees a ripple-free output current, regardless of the number of phases and duty cycle values, and can be adopted to minimize the output ripple, thus prolonging the lifespan of its electrolytic output capacitors. However, conventional ripple cancellers typically require a central controller, which compromises system flexibility and extensibility. In this article, a novel ripple-free decentralized control unit is proposed with only one nonintrusive Rogowski coil sensor required. A ripple attenuator module with the configurable feature is obtained by introducing the proposed control unit, which can be applied to attenuate the output current ripples of MBCs while retaining its remote sense and output voltage trim features. Moreover, the proposed module is robust and can be easily implemented with analog circuits. Based on extensive steady- and transient-state analysis, detailed parameter selection guidelines are carried out to confirm the design procedure. The technique is experimentally validated on a 300-kHz, 12-/1.2-V /40-A three-phase interleaved buck converter. The results demonstrated a 90.3% reduction in output current ripple and a 34.8% reduction in output voltage ripple.