The MM3Z39W with ±5% 37V~41V 300mW 39V SOD-323W Zener Diodes ROHS from JSMSEMI is a voltage-regulating, semiconductor device. It is a single-diode version of a Zener diode, which is designed to maintain a constant voltage between its terminals. It contains a diode made from either silicon or germanium with an impurity concentration higher than a normal rectifier diode. It has a breakdown voltage of 39V and an absolute maximum power dissipation of 300 mW with a range of 37-41V±5%. The device comes with the ROHS certification, which means that it is RoHS-compliant and contains no hazardous substances. It is housed in a SOD-323W package for easy mounting on surfaces. It is typically used in power supplies, voltage stabilization networks, and other applications where a steady voltage regulation is required.