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”