The ISL9518, ISL9518A are highly integrated Narrow VDC
system voltage regulators and battery charger controllers.
Operating parameters are programmable over the System
Management Bus (SMBus). The ISL9518, ISL9518A are
designed for applications where the system power source is
either the battery pack or the output of the regulator/charger.
This makes the max voltage to the system equal to the max
battery voltage instead of the max adapter voltage. The
ISL9518, ISL9518A also include a system to control trickle
charging deeply discharged batteries while maintaining
system voltage at a user defined minimum. High efficiency is
achieved with a DC/DC synchronous-rectifier buck converter,
equipped with diode emulation for enhanced light load
efficiency and AC-adapter boosting prevention. The ISL9518,
ISL9518A can charge two to four series connected
Lithium-ion cells, at up to 8A charge current. The ISL9518
has default settings for 2-cell systems and the ISL9518A has
default settings for 3-cell systems. Integrated MOSFET
drivers and bootstrap diode result in fewer components and
smaller implementation area. Low offset current-sense
amplifiers provide high accuracy.
The ISL9518, ISL9518A provide two open drain digital
outputs that indicate the presence of the AC adapter and
trickle charge state. Trickle charge state and AC adapter
present indicators are also available via SMBus. The
ISL9518, ISL9518A also provide two analog outputs that
indicate the adapter current and battery discharge current
with 4% accuracy.