A Two-Phase Three-Level Buck DC–DC Converter With X-Connected Flying Capacitors for Current Balancing

A Two-Phase Three-Level Buck Converter With Cross-Connected Flying Capacitors for Inductor Current Balancing

## Application

- Envelop Tracking (包络跟踪) and point-of-load applications, because these require small form factor fast-transient converter.
- To balance the inductor current in 2P, 2P3L, 4P3L struture, in which P means phase, L means inductor.

## Disadvantage

- Hard to minimize the mismatches between the two branches.

## Structure

The proposed structure is shown below, however, `the only change is the way of capacitor-connection`

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Waveform $D_1, D_{S1}, D_2, D_{S2}$ control power switches $S_{11}\&S_{24}, S_{12}\&S_{13}, S_{21}\&S_{14}, S_{22}\&S_{23}$. So the voltage of $V_{X1}$ veries $V_{in}→V_{CF1}→V_{in}→V_{in}−V_{CF2}$ and $V_{X2}$ veries $V_{in}→V_{CF2}→V_{in}→V_{in}−V_{CF1}$.