30 A fast recovery diode — what the 50 ns trr buys you
The STTH3002G is a 200 V, 30 A fast-recovery rectifier from STMicroelectronics, built for the output stage of switch-mode power supplies and freewheeling paths in motor drives. Its 50 ns reverse recovery time (trr) keeps the switching node from ringing hard when the diode turns off — that means less snubber loss and a cleaner EMI signature than a standard recovery part would deliver at this current level.
Conduction loss and thermal budget at 30 A
Forward voltage is 1.05 V maximum at 30 A, which puts the conduction loss at 31.5 W before you factor in the switching loss. The D2PAK (TO-263) tab is the cathode terminal — the PCB copper area under that tab sets the junction-to-ambient thermal resistance. At 175 °C maximum junction temperature, the design needs a heatsink or a substantial copper pour to keep the die inside its SOA at full load.
STMicroelectronics lists the STTH3002G as obsolete. No factory orders are accepted; the only channel is independent distribution, where parts are sourced from surplus or last-time-buy inventory.
Package and footprint — D2PAK placement notes
The STTH3002G ships in a D2PAK (TO-263AB) surface-mount package with two leads plus a large tab. The tab is electrically the cathode — the PCB footprint must connect it to the output rail with enough copper area to sink the heat.