Large signal modeling of quasi-resonant buck converter using regulated unified model

摘要

Analyzes the large signal model of a quasi-resonant buck converter using a unified model. The internal resistance of each component in the basic quasi-resonant switch model (QRSW) is taken into consideration. The parameters can be predicted under varying supply voltage and load current. In other words, the variation of switching frequency, which is a controller parameter, can be determined while the output voltage keeps regulating. It is useful for designing an adaptive feedback controller. The power dissipation is analyzed so that the efficiency can be estimated. Moreover, the conduction loss of each component can be found. The critical component in power dissipation is known and the maximum efficiency can be predicted.