A detailed design and evaluation of a high-power density Power Factor Correction (PFC) system, targeting a power output of 3kW is presented. To achieve a compact power stage, a flying capacitor multi-level (FCML) totem-pole boost PFC topology using 100V GaN devices, is employed. By increasing the number of levels in the boost stage, the size of the boost choke and EMI filter can be shrunk, resulting in exceptional power densities. The innovative modular layout provides tight commutation loops while accommodating a higher number of devices in the power stage. Furthermore, active capacitor balancing enhances ruggedness and reliability, enabling mass production of this design. Through experimental evaluation in DC, a peak efficiency of 99.45% and 99.36% is to be obtained at full load with the proposed design. Such high efficiencies push the boundaries of power density. Including the heatsink, boost inductor and unfolding stage, the presented power stage achieves values of around 900W/in3.
