The SMDJ33A with TVS SMC DO-214AB RoHS is an electrostatic discharge (ESD) protection diode manufactured by Yenji. This device is commonly used in modem, set-top box, bluetooth/Wi-Fi modules, and other communications equipment as an ESD protection device. It has an ESD protection capability of up to 25kV (Human Body Model), and is also designed to protect against electrical transients from the Switch Mode Power Supply (SMPS). The SMDJ33A is available in a small, DO-214AB package that is RoHS compliant, and is able to provide enhanced surge protection in limited space applications.