ISL6253
Highly Integrated Battery Charger for Notebook Computers
Typical Diagram
Key Features
- ±0.5% Voltage Accuracy
- ±3% Input Current Limit Accuracy
- ±4% Accurate Battery Charge Current Limit
- Programmable Charge Limit Current, Adaptor Current Limit and Charge Voltage
- Fixed 300kHz PWM Synchronous Buck Controller with Diode Emulation at Light Load
- Output for Current Drawn from the AC Adapter
- AC Adapter Present Indicator
- Fast Input Current Limit Response
- Input Voltage Range 7V to 25V
- Up to 17.6V Battery-Voltage Set Point
- Trickle Charge Mode When Battery Voltage is below 3.0V/Cell
- Supports 2, 3 and 4 Cell Battery Packs
- Control Adapter Power Source Select MOSFET
- Thermal Shutdown
- Aircraft Power Capable
- DC Adapter Present Indicator
- Battery Discharge MOSFET Control
- Less than 10µA Battery Leakage Current
- 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 Available
Description
The ISL6253 is a highly integrated battery charger controller for Li-Ion/Li-Polymer 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.
The constant output voltage can be selected for 2, 3 or 4 series Li-Ion cells with 0.5% accuracy over temperature. It can also be programmed between 4.2V +5% per cell and 4.2V -5% per cell to optimize battery capacity. When supplying the load and battery charger simultaneously, the input current limit for the AC adapter is programmable to within 3% accuracy to avoid overloading the AC adapter, and to allow the system to make efficient use of available adapter power for charging. It also has programmable charging current with 4% accuracy. The ISL6253 provides outputs that are used to monitor the current drawn from the AC adapter, and to monitor for the presence of an AC adapter. The ISL6253 automatically transitions from regulating current to regulating voltage. A conditioning charge feature provides approximately 10% of full scale charge current to safely charge deeply discharged lithiumion (LI+) battery packs when the battery voltage is below 3.0V/cell.
ISL6253 has a feature of automatic power source selection by switching to the battery when the AC adapter is removed or switching to the AC adapter when the AC adapter is available. It also supports aircraft power applications while powering the system and not charging the battery.
Applications
- Notebook, Desknote and Sub-notebook Computers
- Personal Digital Assistants
