AC/DC Power Supply Littelfuse AC/DC Power Supply is a commonly used building block in electronic designs. The components in these power supply building blocks need to be reliable and long-lasting, and Littelfuse offers a range of products that fit those requirements. This portfolio of components covers overcurrent and overvoltage protection, the power stage, and output protection. Typical applications for Littelfuse AC/DC Power Supply products include automotive, solar, industrial, manufacturing, and more.