MMSZ18T1G is a Zener diode manufactured by ON Semiconductor. It is a general purpose device which can be used for voltage regulation and transient suppression. It has a single diode configuration with nominally 18V Zener voltage at zero current and 500mW power rating. It is a compact SOD-123 package with low profile. Its features include high temperature stability, low reverse leakage current, and fast switching speed. It is ideal for different lower current applications including reverse battery protection, surge protection, or voltage reference designs.