The LTC4041 from Analog Devices uses an on-chip bi-directional synchronous converter to provide high-efficiency step-down supercapacitor charging. There is also high current, high-efficiency boost back-up power. When external power is available, the device operates as a step-down battery charger for one or two supercapacitor cells, giving preference to the system load. When the input supply drops below the adjustable PFI threshold, the device switches to step-up regulator operation, capable of delivering up to 2.5A to the system load from the supercapacitor. During a power fail event, its PowerPath control provides reverse blocking and a seamless switchover from input power to back-up power.
Typical applications for the device include ride-through so-called ‘dying gasp’ supplies, high current ride-through 3V to 5V UPS, power meters, industrial alarms, servers and SSDs.
The device is offered in a low profile (0.75mm) 24-lead 4mm x 5mm QFN package with backside metal pad for excellent thermal performance. The device operates from -40C to +125 C, in both E and I grades.