The ISL9211B is an integrated circuit (IC) optimized to provide a redundant safety protection to a Li-ion battery charging system. The IC monitors input voltage, battery voltage, and charge current. When any of these parameters exceeds its limit, the IC turns off an internal N-channel MOSFET to remove power from the charging system to the battery. The IC also monitors its own internal temperature and turns off the N-channel MOSFET when the temperature exceeds +150°C. Together with the battery charger IC and the protection module in a battery pack, the charging system using the ISL9211B has triple-level protection and is two-fault tolerant. The IC is designed to turn on the internal NFET slowly, to avoid in-rush current at power-up. It turns off the NFET quickly when the input is overvoltage, to remove power before damage occurs. The ISL9211B has a logic flag output to indicate a fault condition. The enable input allows the system to cut off the input power, if needed.


  • 24V Max Input Voltage
  • Supports Up To 2.0A Input Current
  • Fully Integrated Protection Circuit for Three Protected Variables
  • High Accuracy Protection Thresholds
  • User Programmable Overcurrent Protection Threshold
  • Responds to Input Overvoltage in Less Than 1µs
  • High Immunity of False Triggering Under Transients
  • Fault Indication for Various Fault Occurrence
  • Easy to Use
  • Pb-Free (RoHS Compliant)


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

tuneProduct Options

Part Number Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active uTDFN Reel 3000


Title language Type Format File Size Date
Datasheets & Errata
star ISL9211B Datasheet Datasheet PDF 639 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
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