400 V phase-control SCR in a TO-220 tab
The STMicroelectronics TYN416RG is a standard-recovery SCR rated for 400 V off-state blocking and 16 A RMS on-state conduction, housed in a through-hole TO-220 package. It is designed for line-frequency phase-control applications such as motor speed controllers, light dimmers, and input rectifier crowbars in power supplies.
The 25 mA maximum gate trigger current (Igt) and 1.5 V maximum gate trigger voltage (Vgt) set the drive requirement from the control IC or transistor. A standard optocoupler or small-signal transistor can fire it directly, but the 40 mA maximum holding current (Ih) means the load must draw at least 40 mA to keep the SCR latched once triggered — below that, the device drops out at the zero-crossing. On-state voltage drop is 1.6 V max at rated current (Vtm), which sets the conduction loss at roughly 16 W for a 10 A average load — heatsink sizing needs to handle that dissipation in a TO-220 tab.
Surge rating and temperature range
Non-repetitive surge current is 160 A at 50 Hz and 167 A at 60 Hz (Itsm) — this is the one-cycle fault withstand for fuse coordination. Off-state leakage is 5 µA max at rated voltage, which is negligible for standby power budgets.
A pin-compatible replacement within the same TO-220 SCR family would need to match the 400 V / 16 A RMS rating and the 25 mA gate trigger threshold — any substitution should be verified against the original BOM's thermal and surge requirements.