50 V, 500 mA general-purpose NPN in SOT-23-3
The TTC1949-Y,LF is a 50 V collector-emitter breakdown, 500 mA collector-current NPN transistor in the standard SOT-23-3 (S-Mini) surface-mount package, rated for 200 mW maximum power dissipation. With a DC current gain (hFE) of 120 minimum at 100 mA collector current and 1 V Vce, it saturates reliably with modest base drive — the 400 mV Vce(sat) at 500 mA is the conduction loss to budget in a 200 mW package. The 100 MHz transition frequency means it switches comfortably into the low-MHz range before gain rolloff limits the edge rate — fine for relay drivers, LED switches, and logic-level translation up to a few hundred kHz.
Active lifecycle, RoHS flag to watch
The part is marked RoHS non-compliant. If your assembly line runs Pb-free reflow profiles, verify the solder-joint reliability at the peak temperature — the SOT-23-3 body handles 150°C junction, but the lead finish may not wet the same as a fully RoHS-compliant part.
Sourcing and cross-reference
The TTC1949-GR,LF carries the same 50 V / 500 mA ratings, same SOT-23-3 package, and same 200 mW power dissipation — the only difference is the hFE bin code (GR vs Y).