Intersil Corporation has introduced the ISL78693, a 3.6V single-cell battery charger that extends the life of LiFePO4 (Lithium Iron Phosphate) batteries used in automotive emergency call (eCall) systems.The ISL78693 battery charger offers up to four times lower leakage current (3µA) than other competing chargers, allowing the eCall system's backup battery to remain charged for a longer period. A demonstration of the ISL78693 can be seen at Intersil booth #E30-11 at the Automotive World Conference from January 18-20 in Tokyo, Japan.
Automakers worldwide are installing eCall systems in their V2I (Vehicle-to-Infrastructure) systems. In the event of an accident, the eCall system automatically transmits the vehicle's location via GPS and contacts the nearest 24/7 emergency call center for assistance. Therefore, V2I eCall systems must be able to operate reliably and autonomously using their backup battery upon alert, even if the vehicle is involved in an accident minutes after being parked for several months.
The ISL78693 battery charger is designed to support emerging eCall systems worldwide, such as Japan's D-Call Net trial, which saves precious seconds that can be lifesaving by automatically transmitting vehicle data to an emergency call center that assesses the severity of a collision and dispatches ground or air assistance. Europe's eCall initiative also provides immediate assistance to drivers involved in a collision, and both ERA-GLONASS in Russia and OnStar® in the United States provide safety and ambulance call services.
The ISL78693's battery temperature monitoring and low 3.6V output voltage help protect and extend the life of popular LiFePO4 batteries. The ISL78693 offers a much simpler and easier-to-use solution than the competition, requiring only five external passive components to program the entire charging platform. Its small 3mm x 3mm DFN package fits easily onto space-constrained PCBs, creating a robust and compact design. It also features a unique charging current thermal fold feature that prevents overheating by automatically reducing the battery charging current to improve reliability.
"Automakers want a qualified automotive battery charger that prevents rapid discharge of the backup battery during a traffic accident or when the vehicle is parked for an extended period," 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 lowest leakage current in the industry and a charging profile optimized for eCall applications.".
Features and Specifications:
• Complete charger for single-cell lithium batteries
• 700nA (typical) and 3uA (max) reverse battery leakage over -40°C to +85°C increases backup battery life, which remains charged when the Vin supply is off
• Up to 1A programmable charging current allows you to trade off battery charging time against heat dissipation and battery life
• Guaranteed operation down to 2.65V after startup, preventing shutdown during cold starts
• 1% initial voltage accuracy provides precise charge level control to extend battery life
• Integrated power transistor and current sensor
• 10% trickle charge preconditions from fully drained battery to the minimum charge level of 2.6V
• NTC thermistor input protects the battery by monitoring temperature and shutting off the charger when the battery is outside the specified charging temperature
• Accepts constant voltage/constant current (CV/CV) chargers DC) of voltage or USB power adapters
• AEC-Q100 Grade-3 Qualified
The 3.6V ISL78693 is pin-compatible with the 4.1V ISL78692 Li-ion battery charger. The charger can be combined with the ISL78268 55V synchronous buck regulator, the ISL78201 2.5A synchronous buck/boost regulator, the ISL78206 2.5A synchronous buck regulator, and the ISL78233 3A synchronous buck regulator to provide a complete 12V lead-acid battery to eCall battery power solution.
