Li-ion/li-polymer Battery Charger Accepting Two Power Sources

The ISL6299 is a fully integrated low-cost single-cell Li-ion or Li-polymer Battery Charger The charger accepts two power inputs, normally one from a USB (Universal Serial Bus) port and the other from a desktop cradle. The ISL6299 is an ideal charger for smart handheld devices that need to communicate with a personal computer via USB The ISL6299 features 28V and 7V maximum voltages for the cradle and the USB inputs respectively. Due to the 28V rating for the cradle input, low-cost, large output tolerance adapters CAN be used safely. When both inputs are powered, the cradle input is used to charge the battery. The charge current is programmable for the cradle input with a small resistor. The end-of-charge current for the cradle input is also programmable by another external resistor. The charger incorporates Thermaguard which protects the IC against over temperature. If the die temperature rises above a typical value of 100C, a thermal foldback function reduces the charge current automatically to prevent further temperature rise. The charger preconditions the battery with low current when the battery voltage is below 2.6V. The By Intersil Corporation