For　the　first　time,　power　loss　comparison　between　20V-rated　devices　including　a　trench　MOSFET　and　four　kinds　of　trench-gate　bipolar-mode　JFETs　(TB-JFETs)　was　carried　out　with　the　help　of　simulation　based　on　static　analysis　and　mixed-mode　dynamic　analysis　using　an　inductive　switching　circuit.　With　at　least　14%　power　loss　improvement　at　1　MHz　and　19%　at　2　MHz　compared　to　that　of　the　trench　MOSFET,　the　calculation　results　have　generated　the　confidence　to　take　normally-on　TB-JFETs,　especially　the　one　with　buried　oxide　(BOX)　to　reduce　the　gate-drain　capacitance　CGD　which　can　provide　6%　more　improvement　at　both　1　and　2　MHz,　as　competitive　candidates　to　replace　trench　MOSFETs　as　a　high-side　switch　in　low-voltage　high-frequency　buck　converters.　Experimental　data　of　CGD　for　normally-on　JFETs　with　and　without　BOX　agree　to　the　simulated　results　and　account　for　the　extra　improvement　in　dynamic　loss　provided　by　the　device　with　BOX.　On　the　other　hand,　the　normally-off　devices　(with　and　without　BOX)　always　perform　the　worst　within　the　commonly　used　frequency　range,　which　implies　their　uselessness.　©2008　IEEE.