A new design method for high efficiency DC-DC converters with flying capacitor technology

Flying capacitor technology is widely used in low power dc-dc converter, especially in power management of the integrated circuit. These circuits have a limitation: high pulse currents will occur at the switching transients, which will reduce the efficiency and cause EMI problems. This makes it difficult to use this technology in high power level conversion. This paper presents a new design method for dc-dc converter with flying capacitor technology. The new method can reduce the high pulse current which usually causes serious problem in traditional converters. Therefore the power level of this new designed converter can be extended to 1 kW or even higher. A 1 kW 42/14 V flying capacitor converter was designed for 42 V automotive system. The experimental results verified the analysis and the prototype achieved the efficiency close to 96% at full load.