30 ns recovery and what it costs in the switching loop
The STTH3R02S is a 200 V, 3 A fast-recovery rectifier from STMicroelectronics' STTH3 series, built for continuous conduction mode (CCM) power stages where reverse recovery charge drives switching loss and EMI. Its 30 ns trr at rated current means the diode exits conduction before the companion MOSFET's voltage rise catches it — a snappy enough recovery to keep the ringing amplitude below what a slow 200 ns part would inject into the gate drive loop. Forward voltage is 1 V maximum at 3 A, a reasonable Vf for a 200 V planar structure. At 3 A continuous the conduction loss is 3 W — the DO-214AB SMC package's junction-to-ambient thermal path handles that with the usual PCB copper area; the 175°C maximum junction temperature gives headroom for ambient temperatures up to 125°C or so in a typical PFC boost or flyback clamp position.
The DO-214AB (SMC) body is 7.1 mm × 6.1 mm with a 2.5 mm height — a standard footprint that shares land pattern with SMB but the wider SMC body handles the 3 A continuous current without exceeding the solder-joint temperature. The cathode is the metal tab side; the anode is the opposite end. Reverse leakage is 3 µA at 200 V rated voltage — negligible for the power dissipation budget, but worth noting that leakage doubles roughly every 10°C above 25°C. At 150°C junction the leakage may reach a few hundred microamps, still small relative to the 3 A forward current.