June 4, 2015 – Linear Technology Korea (CEO Hong Sa-kwak) announced the launch of an integrated lithium-ion battery backup power management system (product name: LTC4040) suitable for 3.5V to 5V power rails that must remain active when main power failures occur. The battery provides significantly more energy than supercapacitors, making it highly suitable for applications requiring backup power for extended durations. The LTC4040 employs an on-chip bidirectional synchronous converter to deliver not only high-efficiency battery charging but also high-current, high-efficiency backup power. When utilizing external power, the device operates as a step-down battery charger for single-cell lithium-ion or LiFePO4 batteries while prioritizing the system load.

When input power drops below an adjustable PFI (Power-Fail Input) threshold, the LTC4040 operates as a step-up regulator capable of delivering up to 2.5A from the backup battery to the system output. In the event of a power failure, the device's PowerPath™ control provides reverse blocking and seamless switchover functionality between input power and backup power. Typical applications of the LTC4040 include fleet tracking and asset tracking, automotive GPS data loggers, automotive telematics systems, electronic toll collection, security systems, communication systems, industrial backup and USB-powered devices.

The LTC4040 also includes OVP (optional overvoltage protection) that protects the IC from input voltages of 60V or higher with external FETs. Through this product's adjustable input current limiting function, operation from current-limited sources is enabled while prioritizing battery charging current over system load current. An external disconnect switch isolates the primary input power from the system during the backup period. The LTC4040's 2.5A battery charger provides eight selectable charging voltages optimized for lithium-ion and LiFePO4 batteries. The device also provides input current monitoring, input power loss indicator, and system power loss indicator.

The LTC4040 is housed in a low-profile (0.75mm) 24-pin 4mm × 5mm QFN package with a metal pad on the back for superior thermal performance. The device operates from –40°C to 125°C and is available in both E and I grades. The LTC4040 is currently in production and pricing starts at $2.90 per unit in E-grade at quantities of 1,000 units. For more information, refer to www.linear.com/product/LTC4040.