In the event of an interruption to the main power supply, the supercapacitors can power the system for up to several seconds. The diode or controller LTC4412 automatically switches the input of the LTM4616 to the supercapacitors if the 5V power is unavailable. The LTC3625/LTC3625-1 are programmable supercapacitor chargers designed to charge two supercapacitors in series to a fixed output voltage (4.8V/5.3V or 4V/4.5V selectable) from a 2.7V to 5.5V input supply. Automatic cell balancing prevents overvoltage damage to either supercapacitor while maximizing charge rate. No balancing resistors are required.