Battery charger extends backup battery life of automotive ecall systems

Intersil has announced the ISL78693, a 3.6V single-cell battery charger that extends the life of Lithium Iron Phosphate (LiFePO4) batteries used in automotive emergency call (eCall) systems. The battery charger offers up to 4x lower leakage current (3uA) than competitive chargers, allowing the eCall backup battery to remain charged for a longer period of time. Automakers worldwide are installing eCall in their Vehicle to Infrastructure (V2I) systems. In the event of a crash, the eCall system automatically broadcasts its location via GPS and contacts the nearest 24-hour emergency call center for help. Thus, systems must be capable of operating reliably and autonomously from the backup battery at a moment’s notice, even if the vehicle is involved in an accident minutes after being parked for several months. The battery charger is designed to support emerging worldwide eCall systems such as Japan’s D-Call Net trial, which saves additional life-saving seconds by automatically transmitting vehicle data to an emergency call center that assesses collision severity and dispatches ground or air-ambulance help. Europe’s eCall initiative also brings immediate assistance to motorists involved in a collision, and both ERA-GLONASS in Russia and OnStar in the United States provide safety and ambulance call services. The battery temperature monitoring and low 3.6V output voltage helps safeguard and extend the life of popular LiFePO4 batteries. The device offers a much simpler and easier to use solution than the competition, requiring only five external passive components to program the full charging platform. The tiny 3mm x 3mm DFN package easily fits on space-constrained PCBs, creating a very robust, small footprint design. It also offers a unique charge current thermal foldback feature that prevents overheating by automatically reducing the battery charging current to enhance reliability. “Carmakers want an automotive-qualified battery charger that prevents rapid discharging of the backup battery during a traffic accident or when the vehicle is parked for an extended period of time,” said Philip Chesley, senior vice president of Precision Products at Intersil. “The ISL78693 leverages Intersil’s innovative power management technology to deliver a solution that provides the industry’s lowest leakage current and a charging profile optimized for eCall applications.”