Advanced power devices for DC-DC conversion

A new generation of semiconductor devices for efficient power management applications is presented. Switch-mode dc-dc synchronous buck converter functional blocks are discussed and different system partitioning solutions are examined. The tradeoff in performance, space, power dissipation, and cost objectives are highlighted. Progress in power trench MOSFETs, hybrid Application Specific MOSFETs (ASMs), and power ICs is discussed. Second generation 30-V W-Gated Trench power MOSFET (WFET) with a transistor density of 300 million cells/inch² exhibit a low specific on-resistance of 15 mΩ.mm² while providing a record-low C_rss/C_iss ratio of 0.04 at V_DS = 15 V. Optimized WFET devices show a low r_(DS)on *Q_gd figure of merit of 10.5 mΩ.nC.