8 A Snubberless Alternistor for AC Load Switching
The T835-600B-TR is an 8 A RMS Alternistor TRIAC from STMicroelectronics' Snubberless™ series, rated for 600 V off-state blocking. The Snubberless construction means the device commutates inductive loads — motors, solenoids, transformers — without the external RC snubber normally required to prevent false turn-on from dV/dt transients. For a 230 VAC fan or pump drawing 6 A continuous, this part switches directly from a microcontroller-driven optotriac or logic-level gate driver. The 80 A (50 Hz) and 84 A (60 Hz) non-repetitive surge current rating handles the inrush from a cold-filament lamp bank or a capacitive power supply on the first half-cycle. The 35 mA gate trigger current (Igt) and 1.3 V gate trigger voltage (Vgt) are compatible with standard 5 V logic via a series resistor — no special driver IC required for basic on/off control.
DPAK Surface-Mount Package and Thermal Management
Housed in a TO-252-3 DPAK (SC-63) surface-mount package, the T835-600B-TR's exposed copper tab on the bottom is the main thermal path. The tab is electrically connected to the MT2 terminal — the PCB layout must account for this when routing the high-current trace and the heatsink plane. A 1 oz copper pad of at least 300 mm² on the top layer keeps the junction below 125 °C at 8 A RMS in still air; the datasheet's thermal resistance curves guide the copper area for the actual load current. The Tape & Reel packaging (TR) suits high-volume pick-and-place assembly. The 35 mA holding current (Ih) ensures the TRIAC stays latched once triggered, even with low-load currents near the zero crossing — important for phase-angle dimming or burst-fire controllers where the load drops below 35 mA for part of the cycle.
Active Lifecycle and Compliance
STMicroelectronics lists the T835-600B-TR as an active product.