8 A RMS, 800 V — what the ratings mean for a BOM line
The T810-800B-TR is an 8 A RMS on-state current TRIAC with an 800 V off-state blocking voltage, packaged in a DPAK (TO-252-3) for surface-mount assembly. The 800 V rating gives headroom on 230/277 VAC mains lines — the peak voltage of a 277 VAC sine wave is 392 V, so the 800 V Vdrm leaves margin for transients without derating the device. This simplifies the BOM count and board area for phase-control or on/off AC switching applications.
Surge, hold, and temperature — the real-world operating envelope
Non-repetitive surge current is rated 80 A at 50 Hz and 84 A at 60 Hz (Itsm). For a motor-start or lamp-inrush event lasting a few cycles, the TRIAC must survive this peak without latching into conduction or failing — the 80/84 A rating covers typical incandescent or capacitive loads on a 8 A RMS line. Holding current (Ih) is 15 mA max. In inductive loads like a fan or solenoid, the current zero-crossing can be slow; a 15 mA Ih ensures the TRIAC commutates off cleanly when the gate signal is removed, rather than staying latched due to a low-level residual current. The junction temperature range spans -40°C to 125°C. At the cold end, the gate trigger current rises (the 10 mA Igt is specified at 25°C); at 125°C junction, leakage current increases but the 800 V blocking capability holds. This temperature grade suits outdoor or unheated enclosures and engine-bay-adjacent environments.
Package and assembly — DPAK footprint for automated lines
The exposed paddle carries the same potential as the middle pin (MT2), so the PCB layout must keep the pad isolated from other nets unless the circuit topology allows it. Supplied in Tape & Reel (TR) or Cut Tape (CT) options, the part is pick-and-place ready for high-volume assembly. The reel quantity is not specified here, but the TR suffix indicates standard 13-inch reel packaging for automated feeders.
Lifecycle and regulatory status
It is RoHS3 compliant (2011/65/EU + 2015/863), which covers the current EU substance restrictions including the four phthalates. No official second-source or pin-compatible cross-reference is recorded from the manufacturer. For a BOM hedge, the parametric match (8 A, 800 V, sensitive gate, DPAK) is the selection criterion; any alternative must match the DPAK footprint and the 10 mA Igt threshold to avoid a gate-drive redesign.