The ISL6255, ISL6255A is a highly integrated battery charger

controller for Li-Ion/Li-Ion 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 and 4

series Li-Ion cells with 0.5 accuracy over temperature. It can

also be programmed between 4.2V+5/cell and 4.2V-5/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 a wide range of programmable charging current. The

ISL6255, ISL6255A provides outputs that are used to monitor

the current drawn from the AC adapter, and monitor for the

presence of an AC adapter. The ISL6255, ISL6255A

automatically transitions from regulating current mode to

regulating voltage mode.

ISL6255, ISL6255A has a feature for 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 provides a DC adapter monitor to support

aircraft power applications with the option of no battery

charging.

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

(ISL6255A)

• 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

• Support 2, 3 and 4 Cells Battery Pack

• Up to 17.64V Battery-Voltage Set Point

• 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

• Support Pulse Charging

• Charge Any Battery Chemistry: Li-Ion, NiCd, NiMH, etc.

• Pb-Free Plus Anneal Available (RoHS Compliant)

Applications

• Notebook, Desknote and Sub-notebook Computers

• Personal Digital Assistant