The ISL6297 is a Dual-Mode Lithium Ion battery charger optimized for cellular phone travel charger applications. It uses Intersil’s patent-pending dual-mode charge technology to minimize the heat normally generated in a linear charger. By minimizing the heat generation, the ISL6297 can be placed inside the connector of the travel charger to completely remove the influence of the adapter cable on the charging performance.

The ISL6297 is an enhancement of the original ISL6292B. New features include improved accuracy, pre-charge circuit verification, and enhanced LED indicator function.

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 bi-color LED. A safety timer prevents charging a dead battery for an excessively long period.

The ISL6297 also features THERMAGUARD™, 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, for charge and non-charge conditions. The thermally-enhanced QFN package further improves the thermal performance of the ISL6297 in spacelimited applications.

• Complete Charger for Single-Cell Li-ion Batteries
• Integrated Pass Element and Current Sensor
• No External Blocking Diode Required
• Very Low Thermal Dual-Mode Operation
• 0.7% Voltage Accuracy with Remote Sense
• Pre-charge circuit verification with LED status indication
• Drives a bi-color LED
• Programmable Safety Timer
• Programmable Current Limit up to 1.5A
• Programmable End-of-Charge Current
• THERMAGUARD™ Charge Current Thermal Foldback
• NTC Thermistor Interface for Battery Temperature Monitor
• Two-Level Ambient Temperature Setting
• Guaranteed to Operate at 2.65V After Start-Up
• Ambient Temperature Range: -20°C to +70°C
• Thermally-Enhanced QFN Packages
• QFN Package:
  • Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat No Leads - Package Outline
  • Near Chip Scale Package footprint, which improves PCB efficiency and has a thinner profile
• Pb-Free Plus Anneal Available (RoHS Compliant)

• PDAs, Cell Phones and Smart Phones
• Portable Instruments, MP3 Players
• Medical Handhelds
• Self-Charging Battery Packs
• Stand-Alone Chargers