描述 The bq77PL157 is a stackable overvoltage protection device for 3, 4, 5 or 6 series cell Li-Ion battery packs. This device incorporates a precise and accurate overvoltage detection circuit with preconfigured threshold limits. Additional features include the ability to stack multiple parts to monitor up to 18 series cells.FUNCTIONEach series cell in a Li-Ion battery pack is compared to an internal reference voltage.If one cell reaches an overvoltage condition, the protection sequence begins.The bq77PL157 starts charging an external capacitor through the CD pin.When the CD pin voltage reaches 1.2 V, the OUT pin changes state and the LVO pin becomes active.If multiple bq77PL157 devices are stacked, the LVIN pin of the next-lower device receives the LVO pin from the above device and similarly starts a shortened delay timer before activating its OUT pin.(No additional isolation or level-shift circuitry is required.)The lowest bq77PL157 in the string is used to activate a power MOSFET located in the low side of the power path.特性 Single IC Li-Ion Protection for 3-Series to 6-Series Cells Stackable to Protect up to 18-Series CellsProgrammable Detection Time DelayLow Power ConsumptionTypical 2-µA to 2.5-µA Normal ModeFixed 4.225 V Overvoltage Threshold Highly Accurate: ±20-mV MAX, TA = 0°C to 50°COutput Activation for Low Side FET(Contact TI for Alternate Output Options: High/Low-side Fuse or FET)Protected Output, Power, and Ground Pins for Added Safety and ReliabilityPermanent or Recoverable Fault Options16-pin Small Outline PackageAPPLICATIONSPrimary or Secondary Level Voltage Protection for Li-Ion Battery Packs for Use in:Power Tools UPS SystemsE-Bikes, Scooters, and Small Mobility VehiclesMedical Devices, Test Equipment, and Industrial Products