An Interleaved High Step Down Conversion Ratio Buck Converter with Closed Loop Control for Low Switch Voltage Stress
This paper presents an interleaved high step down conversion ratio buck converter with closed loop control for low switch voltage stress. In this converter two input capacitors are series charged by the input voltage and parallel discharged by a new two phase IBC (Interleaved Buck Converter) for providing a much higher step down conversion ratio without adopting an extreme short duty cycle. Based on the capacitive voltage division, the new voltage divider circuit in the converter will storing energy in the blocking capacitors for increasing the step down conversion ratio in addition to reducing voltage stresses of active switches. As a result, the converter possesses the low switch voltage stress characteristic. This will allow us to choose lower voltage rat ing switches to reduce both switching and conduction losses, and the overall efficiency is also imp roved. Also the converter features automatic uniform current sharing characteristic of the interleaved phases due to the charge balance of the blocking capacito r, without adding extra circuitry or complex control methods.