Intersil Corporation has announced a single-cell battery charger designed to extend the life of Lithium Iron Phosphate batteries for automotive emergency call systems.
The ISL78693, a 3.6V single-cell battery charger, supports the eCall systems becoming increasingly common in vehicles worldwide.
“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,” says Philip Chesley, senior vice president of Precision Products at Intersil.
Part of the key to extending the life of a battery is to guarantee low leakage current. Battery temperature monitoring and low output voltage (3.6V) let the charger extend the life of LiFePO4 batteries. Reverse battery leakage of 700nA (typical) and 3uA (maximum) over -40°C to +85°C means that the battery remains charged longer when Vin supply is off. Other areas in which this charger is particularly suitable for eCall systems are its size – a 3mm x 3mm DFN package – and a thermal foldback feature, which works in concert with the onboard temperature monitoring. The NTC thermistor input protects the battery and will shut off the charger if the battery experiences temperatures outside the optimal operating range.
It also includes up to 1A programmable charging current, which enables trade-off between battery charging time and heat dissipation. Charging level can be controlled with 1 percent initial voltage accuracy, and a 10 percent trickle charge preconditions a fully trained battery until it achieves the minimum charge level (2.6V).
The charger costs $0.99 for 1k.
