Backup power supplies are necessary for systems whose critical operation and data transmission must be maintained. If the main power supply were to fail, the system must have the capability to quickly switch to the backup supply in order to preserve continuous operations. A power multiplexing (MUXing) circuit should be considered to either select or transition automatically between main and backup power rails.
Texas Instruments' load switch and eFuse portfolio provides the user with a flexible Power MUXing solution for a variety of systems that require a controlled transition between supplies. The solution is further enhanced with capabilities such as adjustable rise time and power good. This application note explores concerns related to power MUXing and demonstrates multiple multiplexing solutions for a wide range of input requirements. Table 1 provides a guide of the recommended load switch or eFuse, based on system requirements.