The 1N5221 from Vishay is a Space-Qualified Zener Diode with a forward voltage of 1.1 V. It has a junction temperature of 175 °C and a power dissipation of 500 mW. This silicon planar power zener diode is lead-free and has a reverse current of 100 uA. It is RoHS-compliant and is ideal for voltage stabilization.