ISL6292B

The ISL6292B uses dual-mode charge technology to minimize the heat in a linear charger. The ISL6292B is a modification of the original ISL6292 and is optimized for cellular phone travel charger applications. The low-heat generation feature of the dual-mode charger enables the charger IC to be placed inside the connector of the travel charger to completely remove the influence of the adapter cable on the charging performance. Working with a current-limited ac/dc converter, the dualmode charger charges a Li-ion battery with the same current profile as a traditional linear charger. The constant charge current is determined by the current limit of the ac/dc converter. The constant output voltage is fixed at 4. 2V. When the battery voltage is below 2. 8V, the charger preconditions the battery with a low trickle-charge current. The charge status is indicated by a tri-color LED. A safety timer prevents charging a dead battery for an excessively long period. The ISL6292B also features a thermal foldback function that automatically reduces the charge current when the internal die temperature exceeds a 100°C limit to prevent further temperature rise. This function removes the concern of thermal failure in the targeted space-limited applications. An ambient temperature monitoring circuit allows users to set two separate temperature limit levels, one for during charge and one for not during charge. The thermally-enhanced QFN package further improves the thermal performance of the ISL6292B in space-limited applications.