Digital Control for Peak Current Mode Controlled Three-Level Flying Capacitor Buck Converter

To address the issue of voltage imbalance in flying capacitors in multilevel topologies, this paper takes the three-level flying capacitor buck converter (3L-FCBC) as the research object and proposes a digital control technique targeting the inductor current ripple peak. This approach can eliminate the subharmonic problem of the inductor current, thereby balancing the flying capacitor voltage. Digital control facilitates hardware simplification and the modulation diversity. The effectiveness of this method has been verified through experiments on a 3L-FCBC prototype with an output of 30V to 10V and a switching frequency of 20kHz.