A 12V to 1V Tri-State DSD Hybrid Converter by Self-Balanced Dual Flying Capacitors with 0.3mV Output Ripple and 90.09% Peak Efficiency

This paper presents a tri-state Double Step-Down (DSD) hybrid converter that enables direct 12 V to 1 V DC-DC power transfer with high voltage conversion ratio and high power density. The converter in this paper combines and improves the advantages of the 3-level and DSD, enabling the use of low-voltage power devices. The dual-loop output reduces the output voltage ripple while expanding the minimum on-time by a factor of six compared to conventional buck converter, facilitating high switching frequency operation. A mirroring device is used to avoid control delays during the master-slave phase. The converter is designed based on a 0.18μm BCD process and can convert 12.0 V to 1.0 V at 1MHz. The converter achieves 90.09% peak efficiency for 12 V to 1 V conversion. It also has a 0.3 mV output voltage ripple at a 1 A current load.