The MMBZ20VA with 1.4A 50nA 28V 19V 17V 21V Unidirectional SOT-23 TVS ROHS manufactured by JSMSEMI is a Transient Voltage Suppressor (TVS) diode designed to protect delicate electronic equipment from electrical overvoltage, particularly in situations where voltage spikes may be created or induced. It comes in a SOT-23 package containing a diode, and is specifically designed for AC and DC circuits. It is capable of withstanding a maximum of 1.4A and is unidirectional, meaning that it will only allow current to flow in one direction. The diode provides protection from voltages up to 28V, 21V, 19V, and 17V, and it can also absorb up to 50nA of electrostatic discharge. It is compliant with the RoHS standard, making it environmentally-friendly.