Demonstration circuit 2464A-B is a supercapacitor charger and backup controller with a hot swappable front end plus supercapacitor health and system monitoring; featuring the LTC3351. The LTC3351 includes a buck supercapacitor charger and a backup boost controller. It has dual input hot swap FETs to control the inrush current when connected and to disconnect the input supply when an over current fault or input power loss occurs. An output ideal diode allows the supercapacitors to supply the output when VCAP is above the set backup voltage. As the capacitor stack voltage drops down to the set output voltage, the LTC3351 will operate as a boost regulator to supply the output until the energy in the supercapacitors is depleted.