The ISL9205 is an integrated single-cell Li-ion or Li-polymer
charger capable of operating at an input voltage as low as
2.5V. The low operating voltage allows the charger to work
with a variety of AC adapters.
The ISL9205 operates as a linear charger when the AC
adapter is a voltage source. The battery is charged in a
standard Li-ion charge profile, i.e. a constant current phase
followed be a constant voltage phase (CC/CV). The charge
current during the constant current phase is determined by
the external resistor connected to the IREF pin. When the
adapter output is a current-limited voltage source and the
current limit is smaller than the programmed constant
current of the IC, the ISL9205 operates as a pulse charger
where the charge current is determined by the current limit of
the AC adapter during the constant current phase. The
ISL9205 operates in a linear mode during the constant
voltage phase in both adapter cases.
The ISL9205 incorporates Thermaguard™ which protects the
IC against over temperature. If the die temperature rises
above a typical value of +100°C , the thermal foldback
function reduces the charge current to prevent further
temperature rise. The ISL9205 includes an external
temperature monitoring function (not available in some
package options). A negative temperature coefficient (NTC)
thermistor is connected between the TEMP pin and GND to
monitor the battery or ambient temperature. The ISL9205
also includes a timer to set the time reference for various
charge time limits. The timer is programmable with an
external capacitor. Two logic inputs and two open-drain logic
outputs are available for controlling the charger and
indicating the charger status. The EN pin enables the
charger, TOEN pin (available in ISL9205) enables the
timeout function so that the charge is terminated when the
preset time limits have been reached. The FAULT pin is an
open-drain output which turns on when a fault condition is
encountered. The STATUS pin is also an open-drain output
which turns on when the charger is delivering current.

Features
• Complete Charger for Single-Cell Li-ion/Polymer Batteries
• Integrated Pass Element and Current Sensor
• No External Blocking Diode Required
• Low Component Count and Cost
• 25mV Voltage Accuracy Over-Temperature and Input
Voltage Range
• 15mV Voltage Accuracy at Room Temperature
• Programmable Charge Current
• Programmable End-of-Charge Current (ISL9205)
• Charge Current Thermal Foldback for Thermal
Protection (Thermaguard™)
• Trickle Charge for Fully Discharged Batteries
• Power Presence and Charge Indications
• NTC Interface (not available in some package options)
• Less than 3µA Leakage Current off the Battery when No
Input Power Attached or Charger Disabled
• Ambient Temperature Range: -40°C to +85°C
• DFN, QFN Packages
• Pb-Free (RoHS Compliant)

Applications
• Mobile Phones
• Blue-Tooth Devices
• PDAs
• MP3 Players
• Stand-Alone Cradle or Travel Chargers
• Other Handheld Devices