System modeling and digital control in modular masterless multi-phase DC-DC converters

System modeling and digital control in a modular masterless multiphase architecture are presented in this paper. Two paralleled control loops, a voltage regulation loop and a current sharing loop, are designed for each phase. The paralleling structure allows both loops to have high bandwidth. Modeling of such systems shows that the voltage loops and current loops can be designed independently assuming identical power stages in each phase. Modeling also shows interaction between voltage and current loops if mismatches among phases are included. Voltage sensing mismatches among phases can result in competition between the two loops. Digital anti-saturation control approaches are proposed to avoid saturation of control loops and adaptively reach a steady state operating point which allows all loops to be active in the presence of voltage sensing errors among multiple voltage loops. Simulation and experimental results with a 2-phase modular masterless multi-phase converter demonstrate the functionality of the proposed control method.