The ISL9209B 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 ISL9209B has triple-level

protection and is two-fault tolerant.

The IC is designed to turn on the internal PFET slowly to

avoid inrush 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 ISL9209B has a logic

warning output to indicate the fault and an enable input to

allow the system to remove the input power.

Features

• 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 Plus Anneal Available (RoHS Compliant)

Applications

• Cell Phones

• Digital Still Cameras

• PDAs and Smart Phones

• Portable Instruments

• Desktop Chargers