The ISL9219 is a fully integrated high input voltage
single-cell Li-ion battery charger. This charger is fully in
compliance with the USB electrical specification. The
charger performs the CC/CV charge function required by
Li-ion batteries. The charger accepts an input voltage up to
28V but is disabled when the input voltage exceeds the OVP
threshold, typically 6V, to prevent excessive power
dissipation. The 28V rating eliminates the overvoltage
protection circuit required in a low input voltage charger.
The fast charge current is programmable with an external
resistor, and the end-of-charge (EOC) current is fixed at
50mA for any input source type. When the input power
source is identified as a USB port, the host controller will
further identify the power type of the port and drive the USBI
pin accordingly.
When the battery voltage is lower than the pre-charge
threshold, which is also programmable with an external
resistor, the charger preconditions the battery with an 85mA
constant current. Charge is complete when the charge current
reduces to the EOC current level during the CV charge phase.
The STAT1 and STAT2 provide unique indication for each
charging condition. An internal thermal foldback function
protects the charger from any thermal failure.
The STAT1, STAT2, TRKL and ACFLT pins are of open drain
type, allowing a simple interface to a microprocessor or an
LED. When no adapter is attached or when disabled, the
charger draws less than 1µA leakage current from the
battery.
Additional features include an OVP protected power-good
source, preconditioning of an over-discharged battery, an
NTC thermistor interface for charging the battery in a safe
temperature range, automatic recharge, and thermally
enhanced QFN package.

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
• 0.7% Voltage Accuracy
• Programmable Charge Currents
• 250µA (Typ) Suspend Quiescent Current
• USB 100mA/500mA Comply
• Charge Current Thermal Foldback for Thermal Protection
• Trickle Charge for Fully Discharged Batteries
• 28V Maximum Voltage for the Power Input
• Charge Status Indication
• Less than 1µA Leakage Current Off the Battery when No
Input Power Attached or Charger Disabled
• Ambient Temperature Range: -40°C to +85°C
• Pb-free (RoHS Compliant)

Related Literature
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
• Technical Brief TB379 “Thermal Characterization of
Packaged Semiconductor Devices”
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN Packages”