800 V, 8 A Snubberless Triac for High-Temperature AC Switching
The STMicroelectronics T835H-8G-TR is an 800 V, 8 A RMS Alternistor triac from the H series, designed for snubberless operation in AC power control. Its 150°C maximum junction temperature and Snubberless topology suit it for high-temperature environments like industrial heating, motor speed controls, and solid-state relays where RC snubber networks are undesirable.
Gate Drive and Holding Current — What 35 mA Means for the BOM
The maximum gate trigger current (Igt) is 35 mA, and the holding current (Ih) is also 35 mA max. This means the gate driver must source at least 35 mA reliably at 1.3 V Vgt to turn the triac on. For low-power MCU GPIOs or optocoupler outputs, a small driver transistor or Darlington pair is needed. The 35 mA Ih ensures the triac stays latched once triggered, even with lightly inductive loads down to that current level.
Surge Current and Thermal Margin for Inrush-Heavy Loads
Non-repetitive surge current is rated at 80 A (50 Hz) and 84 A (60 Hz). For loads like incandescent lamps or motor starts that draw 5–10× the steady-state current for a few cycles, this surge rating provides the headroom. The 150°C junction temperature rating gives additional thermal margin in enclosed or poorly ventilated enclosures, common in industrial panel applications.
Package and Mounting — D²PAK Surface Mount
Supplied in TO-263-3 (D²Pak) surface-mount package with 2 leads plus tab.