View mm3z52xx-series datasheet:

Zowie Technology Corporation MM3Z5221BH~MM3Z5267BH SILICON PLANAR ZENER DIODES Lead free product PINNING Halogen - free type PIN DESCRIPTION Cathode 1 Anode 2 Silicon Planar Zener Diode in a small plastic SMD SOD-323 package 2 1 Features • Total power dissipation: Max. 300 mW Top View Simplified outline SOD-323 and symbol • Small plastic package suitable for surface mounted design • Tolerance approximately ± 5% O Absolute Maximum Ratings (Ta = 25 C) Parameter Symbol Value Unit Total Power Dissipation Ptot 300 mW O Operating Junction and Storage Temperature Range Tj, TS - 55 to + 150 C O Characteristics at Ta = 25 C Parameter Symbol Max. Unit O RθJA Thermal Resistance Junction to Ambient Air 625 C/W Forward Voltage VF 0.9 V