The MMSZ5245B is a Zener diode SOD-123 RoHS from Changjiang. It is a type of electronic component used in electronics circuit design, and is a kind of diode designed specifically to regulate the voltage in an electronic device. It is composed of two semiconductor junctions connected in series, designed to allow current to travel in one direction only. It has a rated voltage between 4.7V and 5.3V, a maximum power dissipation of 250 mW, and a maximum reverse voltage of 5.3V. It also has a maximum reverse leakage current of 0.15uA, and an operating temperature range of -55°C to +150°C. This diode is RoHS compliant, which means it meets the environmental standards for safe disposal and use of certain hazardous substances.