The 5.0SMDJ54A is an electronic part made by the company Yageo. It is a Transient Voltage Suppressors with a Surface Mount Chip (DO-214AB) in conformity with Restriction of Hazardous Substances (RoHS) regulations. It is designed to protect sensitive electronic components from voltage surges, and can reduce overall component count for more compact designs. The 5.0SMDJ54A is rated for up to 5.0V reverse stand-off voltage and is able to dissipate up to 1.5W of power.