SPRUI97E May 2017 – September 2025
The TPS3808G50 voltage supervisor circuit, U105, monitors the main power input and initiates a power-down sequence, if the main input voltage drops below 4.65V. Since some external power supplies may droop during rapid changes in load current, this can trigger an unexpected shut-down and restart sequence that resets the SOC. U105 can be replaced with a TPS3808G33 voltage supervisor device that triggers at 3.07V. This is still above the minimum input voltage of the PMIC. However, this lower threshold voltage may require additional capacitance to be added at the input to the PMIC to allow the power-down sequence to complete before the input voltage collapses.