TDZV Zener Diodes ROHM Semiconductor TDZV Zener Diodes are highly reliable and are ideal for voltage regulation applications. The TDZV devices are offered in a small mold SOD-323HE package, operate at a 5.1V to 18V Zener voltage range, and have 500mW of power dissipation. ROHM Semiconductor TDZV Series Zener Diodes are silicon epitaxial planar in structure.