Low on-resistance SOI power MOSFET using dynamic threshold (DT)concept for high efficient DC-DC converter

摘要

A new low on-resistance (R_on) power MOSFET using thedynamic threshold (DT) concept was studied. The R_on at lowgate-driving-voltage was effectively improved using the DT concept. Wecarried out numerical simulations based on the experimentalmeasurements. It was clarified that the R_on of the thin-filmDT-SOI power MOSFET was 30% lower than that of conventional thin-filmSOI power MOSFETs at a gate voltage of 1.2 V. Although theR_on of the DT-SOI device was lower, the total gate charge wasslightly larger than that of conventional devices because of anadditional device structure. The lower R_on reduces the powerloss of a synchronous rectifier while the larger gate charge increasesit. We compared the power loss of the thin-film DT-DOI device as thesynchronous rectifier of a DC-DC converter with that of a conventionalthin-film SOI device. It was clarified that the power loss of the newpower MOSFET was 36% lower than that of the conventional thin-film SOIdevice at a gate voltage of 1.2 V