Description

This reference design automatically provides a back-up voltage during a power interruption. It manages the charging of supercapitors and provides reverse blocking protection. The maximum supercapacitor charging current and voltage can be adjusted. When the input voltage fails a buck-boost converter (TPS63802) takes over and generates a constant backup voltage. The supercapacitor capacitance and voltage define the energy that is available for the backup. The PMP30693 provides a stable backup output of 3.7 V at 300 mA for more than 100 s until the output voltage drops.