High-performance voltage-regulator modules for the new generation of microprocessors have many strict and challenging specifications, such as high power density, high output-current capability, low output-voltage deviation and fast transient response. A dual mode control multiphase DC/DC converter is presented, which combines voltage and hysteretic control modes and has the merits of high efficiency, simple control and fast transient response. It can also be used for single-phase and built-in integrated circuits without requiring additional cost and space. The operating principles and design considerations are analysed and discussed in detail. A 1.3 V/80 A four-phase laboratory prototype is simulated and implemented to verify the feasibility of the proposed scheme. The results prove to be satisfactory