Low Cost Multi-Chemistry Battery Charger Controller

The ISL6251, ISL6251A is a highly integrated battery charger controller for Li-Ion/Li-Ion polymer batteries and NiMH batteries. High efficiency is achieved by a synchronous buck topology and the use of a MOSFET, instead of a diode, for selecting power from the adapter or battery. The low side MOSFET emulates a diode at light loads to improve the light load efficiency and prevent system bus boosting.

Features
• ±0.5% Charge Voltage Accuracy (-10°C to +100°C)
• ±3% Accurate Input Current Limit
• ±3% Accurate Battery Charge Current Limit
• ±25% Accurate Battery Trickle Charge Current Limit (ISL6251A)
• Programmable Charge Current Limit, Adapter Current Limit and Charge Voltage
• Fixed 300kHz PWM Synchronous Buck Controller with Diode Emulation at Light Load
• Output for Current Drawn from AC Adapter
• AC Adapter Present Indicator
• Fast Input Current Limit Response
• Input Voltage Range 7V to 25V
• Supports 2, 3 and 4 Cells Battery Pack
• Up to 17.64V Battery-Voltage Set Point
• Thermal Shutdown
• Support Pulse Charging
• Less than 10µA Battery Leakage Current
• Charge Any Battery Chemistry: Li-Ion, NiCd, NiMH, etc.
• Pb-Free (RoHS Compliant)

Applications
• Notebook, Desknote and Sub-notebook Computers
• Personal Digital Assistant