1. INTERLEAVED BOUNDARY CONDUCTION MODE (BCM) BUCK
POWER FACTOR CORRECTION (PFC) CONVERTER
ABSTRACT:
An interleaved boundary conduction mode power-factor-correction buck converter that maintains
high efficiency across entire load and line range is proposed. The adaptive master-slave interleaving method
maintains stable 180° out-of-phase operation during any transient. By interleaving two parallel-connected
buck converters, the input current ripple is halved while the ripple frequency is doubled, which leads to a
smaller differential mode line filter. The line current harmonic distortion is analyzed to examine the
allowable output voltage range while meeting harmonic regulations. The operation and performance of the
proposed circuit is verified on a 300 W, universal line experimental prototype with 80 V output. The
measured efficiencies remain above 96% down to 20% of full load across the entire universal line range.
Even at 10% of full-load condition, the efficiency remains above 94%. The input current harmonics also
meet the IEC61000-3-2 (class D) standard.