The TTC004B,Q is a 160 V, 1.5 A NPN bipolar transistor in a TO-126N through-hole package, rated for 10 W continuous power dissipation at a junction temperature up to 150 °C. Vce saturation is specified at 500 mV max at a forced-beta condition of 50 mA base drive into 500 mA collector current, which gives a reasonable guide for saturated-switch designs at moderate current.
The TO-126N (also listed as TO-225AA / TO-126-3) is a three-lead through-hole package with a metal tab for heatsinking — the tab is internally connected to the collector, so the PCB copper or an external heatsink must account for that electrical potential. Mounting is through-hole, so the lead pitch and hole pattern match the standard TO-126 footprint; the Bulk packaging means it ships as individual units, not on tape and reel.
Lifecycle and compliance
The collector cutoff current (ICBO) is specified at 100 nA maximum, which is a standard figure for a silicon transistor of this voltage class and indicates a clean junction.