DDZ 0.5W Surface Mount Precision Zener Diodes Diodes Incorporated DDZ 0.5W Surface Mount Precision Zener Diodes feature 500mW power dissipation on FR-4 PCB and a very tight tolerance on VZ. Diodes Incorporated 0.5W Surface Mount Precision Zener Diodes are ideally suited for automated assembly processes and are considered to be 'Green' devices, according to Diodes Incorporated's 'Green' policy.