600 V, 1 A — where this MOSFET fits
The STD1NK60T4 is an N-channel enhancement-mode MOSFET from ST's SuperMESH™ series, rated for 600 V drain-source and 1 A continuous drain current at 25 °C case temperature. It comes in the DPAK (TO-252) surface-mount package and operates over the full military junction temperature range of -55 to 150 °C. This part is built for low-power offline switch-mode supplies, auxiliary flyback converters, PFC stages in lighting ballasts, and any 600 V bus where the load stays under 1 A. The SuperMESH™ technology delivers a low gate charge of 10 nC at 10 V and input capacitance of 156 pF at 25 V, which means a modest gate-drive signal from a PWM controller IC is enough to switch it cleanly — no external driver buffer needed in many designs.
8.5 Ω Rds(on) — what it costs you in conduction loss
The maximum on-resistance is 8.5 Ω at 500 mA drain current with 10 V gate drive. At 1 A the Rds(on) will be higher — the spec is taken at half the rated current.
There is no official second-source or pin-compatible alternate listed in the ST portfolio; the STD1NK60T4 is a standalone variant in the SuperMESH™ 600 V 1 A class.