LTC®4041 is a complete supercapacitor backup system for 2.9V to 5.5V supply rails. It contains a high current step-down DC/DC converter to charge a single supercapacitor or two supercapacitors in series. Its adjustable input current limit function reduces charge current to protect the input supply from overload while an external disconnect switch isolates the input supply during backup. When the input supply drops below the adjustable PFI threshold, the 2.5A boost regulator delivers power from the supercapacitor to the system output. An internal supercapacitor balancing circuit maintains equal voltages across each supercapacitor and limits the maximum voltage of each supercapacitor to a pre-determined value. Typical applications are ride-through Dying Gasp supplies, high current ride-through 3V to 5V UPS, power meters/industrial alarms, servers/solid state drives.