A Reconfigurable 3-Level Buck Converter With Supply Voltage Dynamic Split for Loop-Free Rapid VCF-Balancing and Dead-Zone Seamless Transition

초록

This brief presents a supply voltage (VIN) dynamic split to overcome practical limitations of multi-level (ML) buck converters. The ML buck converters using flying capacitors (C-F) suffer from both C-F voltage (V-CF) imbalance and random switching at near dead-zone conversion ratio (CR = VOUT/VIN). The proposed 3-level buck converter with input capacitor (CIN) dynamic reuse adopts VIN half-split balancing (VHSB) for loop-free rapid V-CF balancing. In addition, VIN quarter-split transition (VQST) is applied to prevent irregular output voltage (VOUT) ripples and acoustic noise due to random switching at near dead-zone CR. Fabricated in 28nm, the chip provides high ILOAD of 1.2A for VIN up to 3.6V using only 1.8V low-voltage transistors. Moreover, the converter achieves an excellent peak efficiency of 95.2%.

키워드