A Two-Phase Hybrid Switched Capacitors Converter with Interleaving Control Scheme for Flying Capacitors Self-Balancing

This paper presents a dual-path power stage with an interleaving control scheme in a two-phase hybrid switched capacitor converter. In a conventional three-level converter, the flying capacitor voltage is not self-balanced and thus extra calibration is required to overcome parameter and timing mismatches, parasitic capacitors, etc. The proposed converter obtains a self-balanced flying capacitor voltage with an interleaving control scheme. And then, the non-ideal effects are also calibrated without an additional cost. In addition, there are two series power switches in the discharge path in the three-level converter. But in the proposed power stage, there is only one power switch. Therefore, the conduction loss is reduced dramatically in each de-energizing phase. The converter is implemented with a conversion from 12.0 V to 1.0 V at a 1-MHz switching frequency, based on a $0.15-\mu\mathrm{m}$ highvoltage BCD process. The simulation shows that the flying capacitor voltages are self-balanced within only one switching cycle. The peak efficiency of 89.8% is achieved by this converter under a 3-A current load.