12 V Zener — regulation and clamping in a SQ-MELF package
The 1N6326US/TR: This is a 12 V Zener diode rated for 500 mW continuous power dissipation in a surface-mount SQ-MELF B package. The ±5% tolerance on the nominal Zener voltage means the actual breakdown voltage for any given unit falls between 11.4 V and 12.6 V — tight enough for most voltage-reference and clamping duties in low-power analog and digital circuits. Maximum impedance (Zzt) is 7 Ohms at the test current. Lower impedance means the Zener holds its voltage more tightly as the current through it varies — useful when the diode is used as a shunt regulator feeding a small load that draws a few milliamps.
Temperature range and reverse leakage
Reverse leakage is specified at 1 µA maximum at 9 V reverse bias — well below the Zener knee, so the diode does not load the circuit appreciably until the applied voltage approaches the breakdown region. Forward voltage is 1.4 V maximum at 1 A forward current. This matters if the diode is used in a bidirectional clamp or as a rectifier in a low-voltage rail — the forward drop at high current is higher than a Schottky but typical for a Zener junction.
SQ-MELF B — board-fit and assembly
The SQ-MELF B (Surface Mount Qualified Metal Electrode Face) package is a hermetic, solderable ceramic body with metal end caps. It handles the full -65°C to +175°C temperature range without die-attach fatigue, and the end-cap termination is compatible with standard reflow profiles. The Tape & Reel delivery supports automated pick-and-place assembly.