Highly integrated 2.5A backup power manager provides high efficiency charging and system backup for up to 2 supercapacitors

Analog Devices Inc. (ADI) announces the Power by LinearTM LTC4041, a complete supercapacitor backup power management system for 2.9V to 5.5V power rails that must remain active in the event of a primary power failure . Supercapacitors have higher power densities than batteries, making them ideal for systems that require high peak backup power in a short period of time.

The LTC4041 uses an on-chip bidirectional synchronous converter to provide high efficiency step-down supercapacitor charging and high current, high efficiency step-up backup power. When an external power supply is available, the device acts as a step-down battery charger for one or two supercapacitor batteries, while giving priority to system loads. When the input supply drops below the adjustable power supply fault input (PFI) threshold, the LTC4041 switches to the boost regulator operating mode, which provides up to 2.5A to the system load through the ultracapacitor. In the event of a power failure, the device's PowerPathTM control provides reverse isolation and seamless switching between input and backup power. Typical applications for the LTC4041 include traversing “power-off alarm” power supplies, high current traversal 3V–5V uninterruptible power supplies (UPS), power meters, industrial alarms, servers, and solid-state drives.

The LTC4041 includes an optional overvoltage protection (OVP) function circuit with an external FET that protects the IC from input voltages above 60V. An internal supercapacitor balancing circuit maintains equal voltage across each supercapacitor and limits the maximum voltage of each supercapacitor to a predetermined value. Its adjustable input current limit allows operation with current-limited power supplies while preferentially providing system load current instead of battery charging current. An external disconnect switch isolates the main input power from the system during backup. The device also includes input current monitoring, input power fault indicators, and system power fault indicators.

The LTC4041 is available in a low profile (0.75mm) 24-pin 4mm x 5mm QFN package with a metal pad on the back for superior thermal performance. Both the E and I versions of the device operate over the –40°C to 125°C temperature range.

Relevant LTC40 series products

Author：Brittany Antonia （The author of article owns the copyright.）