1.6 kV blocking, 55 A RMS — where this SCR fits
The Vishay VS-40TPS16LHM3 is a standard-recovery SCR rated for 1.6 kV off-state voltage and 55 A RMS on-state current, housed in a TO-247AD through-hole package.
Gate trigger current is specified at 150 mA maximum, with a maximum gate trigger voltage of 2.5 V. This is a moderate-drive SCR — a standard optocoupler or pulse transformer with a 12 V supply and a 100 Ω series resistor can fire it reliably. On-state voltage (VTM) is 1.92 V maximum at rated current, so conduction losses at 35 A average work out to roughly 67 W; plan the heatsink for that dissipation at the 125°C junction limit.
Surge rating and holding current
Non-repetitive surge current is 500 A at 50 Hz half-sine — this sets the fuse I²t coordination floor and the inrush capability for capacitive or motor-start loads. Holding current is 300 mA maximum, meaning the load must draw at least that much to keep the SCR latched after the gate pulse ends. Off-state leakage is 500 µA maximum at rated voltage, negligible for most designs but worth checking in high-impedance load-sharing circuits.
Package and mounting — TO-247AD through-hole
The TO-247AD package (TO-247-3 variant) uses a through-hole mounting with a large metal tab for heatsink attachment. The tab is electrically connected to the cathode — insulate it from ground or use a thermal pad. The package is supplied in Tube.