Low Voltage Trench-Gate MOSFET Power Losses Optimization in Synchronous Buck Converter Applications

The paper deals with the optimal selection of low side and high side switches, in a synchronous buck converter, based on energy losses as well as dynamic switching characteristics as focused parameters. The MOSFET in trench-gate technology investigated is based on a strip-geometry layout which allows an excellent trade-off between the on-resistance and the gate charge. In the proposed paper main technology issues are shortly recalled and the advantages deriving from the improved device are focused. Furthermore, the switching behavior in actual synchronous buck converter circuit applied as a power supply for auxiliary electronic automotive accessories has been evaluated. Last generation trench-gate MOSFET at different current ratings are tested in order to give evidence to the effectiveness improvements achieved by using the selection of correct devices. Finally, experimental results on the converter performances such as switching transients, power losses and thermal behavior are carried out.