The Dynamic Analysis of Power MOSFET in Buck Converter

The switching transient process of a high power MOSFET in converter is more complicated; therefore, the study of these processes can make sense of learning the operation and do it safety operation. The contributions of this paper are as follows: 1) the power MOSFET operates from pinch-off region to linear region through out the active region when it works in the turn-on process, the small signal model and large signal model will be employed to analysis it; 2) the parasitic parameters have been involved to analyze the transient process in the converter because these including the semiconductors and the circuit play an important role; 3) Based on the equivalent circuits of power MOSFET and its parasitic parameters, the switching process of the power MOSFET has been analyzed qualitatively as well as quantitively. As result, the transient loss of the MOSFET has been calculated for BUCK converter. The proposed analytic method for the transient operational processes has given out a new fundamental approach to learn the converter.