A 2A 4MHz Dual-Phase ZDS Hysteretic DC-DC Buck Converter With Peak Efficiency Above 90%

This paper presents a 2A 4MHz dual-phase zero-delay synchronized (ZDS) hysteretic DC-DC buck converter for large current application such as outdoor units of air conditioners. With an on-chip synchronizer for phase synchronization, the proposed buck converter employs a ZDS hysteretic feedback control loop for accurate voltage regulation and a phase switcher cooperated with an operating mode switcher for high efficiency in full load range. The 2A 4MHz dual-phase buck converter was designed in TSMC 55nm process. The post-simulation results show that the peak efficiency reaches 90.1% when the load is 450mA, and the efficiency is almost higher than 80% in the full load range. Accurate current balance is achieved between two phases, which solves the problem of heating concentration effectively.