600 V, 17 A, 220 mΩ — hard-switching workhorse, now obsolete
In a TO-220 through-hole package, it targets power-factor-correction stages, flyback converters, and two-switch forward converters in industrial and consumer SMPS designs.
STMicroelectronics lists the STP21NM60N as obsolete. Date codes will vary; typical stock carries date codes from the final production runs. Counterfeit screening is advised when buying through the spot market — independent brokers can provide lot trace and X-ray/decapsulation reports on request.
Key ratings and their design impact
The 600 V drain-source breakdown voltage gives 80% derating margin on a 400 V DC bus — adequate for single-ended PFC and flyback stages with reasonable leakage inductance spikes. The 17 A continuous drain current is rated at 25°C case temperature; real-world current capability is lower and follows the 140 W power dissipation ceiling. The 220 mΩ Rds(on) at 10 V gate drive means at 8.5 A the conduction loss is about 16 W — the TO-220 package with a proper heatsink is mandatory. The 1900 pF input capacitance at 50 V is moderate — a typical 1 A gate driver will switch it in the 30–50 ns range.