Now, supercapacitors have higher power density than batteries, making them suitable for systems whose applications require high peak power backup for brief time intervals. To support such applications, Analog Devices’ LTC4041 uses an on-chip bidirectional synchronous converter to provide high efficiency step-down supercapacitor charging, as well as high current, high efficiency boost backup power.
When external power is available, the device operates as a step-down battery charger for one or two supercapacitor cells while giving preference to the system load. When the input supply drops below the adjustable PFI threshold, the LTC4041 switches to step-up mode operation and can deliver up to 2.5A to the system load from the supercapacitor(s). During a power fail event, the device’s PowerPath control provides reverse blocking and a seamless switchover from input power to backup power. Typical applications for the LTC4041 include ride-through “dying gasp” supplies, high current ride-through 3 V to 5 V UPSs, power meters, industrial alarms, servers, and solid-state drives. Figure 2 shows a typical LTC4041 application schematic.