Zener TVS diode for general-purpose transient suppression
Its single bidirectional channel clamps both positive and negative overvoltages, so a single device replaces two unidirectional diodes on AC-coupled or bipolar signal paths. The SQ-MELF B package is a surface-mount cylindrical body with wraparound metallization — common in high-reliability and military/aerospace designs where the MELF footprint offers better solder-joint fatigue life than a comparable SMB/SMC package.
Clamping window and temperature range
The reverse standoff voltage is 27.4V typ, breakdown minimum is 34.2V, and maximum clamping at 10A peak pulse current is 49.9V. That 22.5V window between standoff and clamp gives the designer margin to absorb repetitive surges without triggering false clamping on normal 24V bus ripple. The extra 25°C headroom matters in under-hood, downhole, or avionics environments where ambient heat plus self-heating from repetitive pulses can push junction temperature above 150°C.
The base product number is 1N6119; this variant is the surface-mount SQ-MELF version, not the through-hole axial-lead version.