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