Intersil’s 4.1-V single-cell battery charger, the ISL78692, is designed to extend the life of lithium-ion (Li-ion) batteries in automotive emergency call (eCall) systems. Its low leakage-current dissipation (3 µA), allowing the backup battery to remain charged for a longer period of time. Thanks to an NTC thermistor input, the device can monitor the battery’s temperature, shutting off the charger when the battery is outside the specified charging temperature.
Charging current is programmable up to 1 A, which enables design tradeoffs of battery-charging time against heat dissipation and expected battery lifetime. Only five external components are needed to program the charging current. The charger’s 1% initial voltage accuracy provides precise control of charging level to extend the operating lifetime of battery.
The AEC-Q100 grade 3-qualified ISL78692 comes in a 3- by 3-mm DFN package to save printed-circuit-board space. The ISL78692 also offers a charge current thermal foldback feature that prevents overheating by automatically reducing the battery-charging current, creating a very robust, small footprint design.