35 ns trr — what it buys you in a switching circuit
The BYW98-200RL is a standard fast-recovery rectifier from STMicroelectronics, rated for 3 A average forward current and 200 V repetitive reverse voltage. Its 35 ns reverse recovery time (trr) makes it suitable for freewheeling and snubber diodes in medium-frequency switching supplies, motor drives, and flyback converters where a standard recovery part would cause excessive switching loss or ringing. The DO-201AD axial package is a through-hole form factor common in legacy power supplies and industrial control boards — not a surface-mount design.
Obsolete — plan your BOM accordingly
STMicroelectronics lists the BYW98-200RL as Obsolete. No official successor order code appears in the record. For new designs, look at current fast-recovery diodes in the same voltage and current class — the 35 ns trr and DO-201AD footprint are the constraints to match. Stock the reels dry: this is a through-hole axial part, not moisture-sensitive, but store in a cool, dry environment to keep the leads solderable.
Forward drop and leakage — the thermal budget numbers
Maximum forward voltage is 1.2 V at 9 A pulsed current — that's the surge condition, not the continuous drop. At the 3 A average rating the Vf will be lower, but the 1.2 V figure gives you the worst-case conduction loss for heatsink sizing. Reverse leakage is 10 µA at 200 V, negligible at room temperature but it doubles with every 10 °C rise in junction temperature; the junction is rated to 150 °C max. If the part runs hot, budget for leakage current in the bias network.