The 1SMA4737A with Zener Diodes SMA RoHS is an electronic component manufactured by Jingdao. It is a single, non-repetitive peak, reverse break-down voltage of 37V, at a surge current of 5A. The device is comprised of three subsections, which are formed by two semiconductor junctions. The center subsection is the Zener diode, which provides a very stable reverse voltage drop when current passes through the device. The two side subsections form the rectifying diodes that protect the zener diode from excessive forward or reverse voltage. This part is RoHS compliant and is an economical solution for applications such as precision voltage regulation, voltage reference, temperature compensation, and surge protection.