The ISL9209C is an integrated circuit (IC) optimized to provide a redundant safety protection to a Li-ion battery from failures of a charging system. The IC monitors the input voltage, the battery voltage, and the charge current. When any of the three parameters exceeds its limit, the IC turns off an internal P-Channel MOSFET to remove the power from the charging system. In addition to the above protected parameters, the IC also monitors its own internal temperature and turns off the P-Channel MOSFET when the temperature exceeds +140°C. Together with the battery charger IC and the protection module in a battery pack, the charging system using the ISL9209C has triple-level protection and is two-fault tolerant. The IC is designed to turn on the internal PFET slowly to avoid in-rush current at power-up but will turn off the PFET quickly when the input is overvoltage in order to remove the power before any damage occurs. The ISL9209C has a logic warning output to indicate the fault and an enable input to allow the system to remove the input power.


  • Fully Integrated Protection Circuit for Three Protected Variables
  • High Accuracy Protection Thresholds
  • User Programmable Overcurrent Protection Threshold
  • Input Overvoltage Protection in Less Than 1µs
  • High Immunity of False Triggering Under Transients
  • Warning Output to Indicate the Occurrence of Faults
  • Enable Input
  • Easy to Use
  • Thermal Enhanced TDFN Package
  • Pb-Free (RoHS Compliant)


  • Cell Phones
  • Digital Still Cameras
  • PDAs and Smart Phones
  • Portable Instruments
  • Desktop Chargers

Product Options

Part Number Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active TDFN Tube 75
Active TDFN Reel 6000

Documentation & Downloads

Title language Type Format File Size Date
Datasheets & Errata
ISL9209C Datasheet Datasheet PDF 981 KB
Application Notes & White Papers
Five Easy Steps to Create a Multi-Load Power Solution White Paper PDF 846 KB
AN1681: Grounding Techniques Application Note PDF 509 KB
AN1684: Nonideality of Ground Application Note PDF 397 KB
PCN15046 - Wafer Fabrication Site Change for Listed Intersil Products - Global Foundry P6 Process transfer to Palm Bay - Phase II Product Change Notice PDF 398 KB
PCN10055 - Alternate Bond Wire Material for Assembly of the Listed Intersil DFN/QFN Packaged Products - STATS ChipPAC Malaysia Product Change Notice PDF 248 KB
TB363: Guidelines for Handling and Processing Moisture Sensitive Surface Mount Devices (SMDs) Other PDF 293 KB
TB389: PCB Land Pattern Design and Surface Mount Guidelines for QFN Packages Other PDF 958 KB
TB379: Thermal Characterization of Packaged Semiconductor Devices Other PDF 653 KB