Circuit protection on AC and DC power lines is necessary for just about any device. Varying levels of exposure to lightning and switching transients, poor line voltage regulation in rural and developing areas, and inconsistency among different grids around the globe mean that there is no single recognized universal solution.
The problem can be examined from the standpoint of the reliability and robustness of the protection solution as well as the flexibility to adapt solutions to varying requirements while keeping manufacturing changes to a minimum. Always wanting to achieve higher density and higher performance designs, it can be challenging to address all circuit protection concerns. The Surge Protective Devices (SPDs) standard, UL 1449, sets forth requirements for recognition. Again, there is no single universal solution.
This white paper from Bourns examines the use of traditional Metal Oxide Varistor (MOV) devices and their performance and failure modes in various scenarios. Then it presents an innovative component hybrid solution that addresses some of the MOV shortcomings and enables greater flexibility in applications. Bourns has leveraged existing technology to provide a UL 1449 recognized solution that enhances performance and flexibility for front-end circuit protection in a footprint compatible device.