A 92.6% Efficiency Rotated Hybrid Step-Down Converter With Rotated Parallel Operation for Flying Capacitor Charge Balance and Fast Transient Response

The conventional capacitor-switch-inductor (C-S-L) topology suffers from significant conduction loss and sluggish transient response due to the series power switches conduction inherent in its structure. To address these limitations, the proposed rotated hybrid converter adopts a rotated mechanism and parallel conduction within the capacitor-two-switch-inductor (C-2S-L) topology, effectively reducing current stress on components. This approach enhances efficiency while mitigating the effects of parasitic inductance from bond wires. During transient conditions, all C-2S-L stages can be simultaneously activated, enabling a near-full duty cycle (D). Experimental results demonstrate a minimal undershoot of 96 mV and a fast settling time of 0.92 μs during a load step from 2 A to 10 A within 20 ns. Additionally, the converter integrates phase shedding, dynamically adjusting the number of active phases according to load conditions to optimize efficiency across a broad load range. Therefore, the proposed C-2S-L topology achieves a peak efficiency of 92.6% at an output voltage (V<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>OUT</roman></sub>) of 1.2 V and a load current (I<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>LOAD</roman></sub>) of 3A.