The bq2944x is a secondary overvoltage protection IC for 2-series, 3-series, or 4-series cell Li-Ion battery packs that incorporates a high-accuracy precision overvoltage detection circuit.

FUNCTION

The voltage of each cell in a battery pack is compared to an internal reference voltage. If any cells reach an overvoltage condition, the bq2944x device starts a timer that provides a delay proportional to the capacitance on the CD pin. Upon expiration of the internal timer, the OUT pin changes from a low state to a high state. An optional latch configuration is available that holds the OUT pin in a high state indefinitely after an overvoltage condition has satisfied the specified delay timer period. The latch is released when the CD pin is shorted to GND.

• 2-Series, 3-Series, or 4-Series Cell Secondary Protection
• External Capacitor-Controlled Delay Timer
• Low Power Consumption ICC < 2A Typical [VCELL(ALL) < VPROTECT]
• High-Accuracy Overvoltage Protection: ±25 mV with TA = 0°C to 60°C
• Fixed Overvoltage Protection Thresholds: 4.30V, 4.35V, 4.40V, 4.45V, 4.50V
• Small 8L QFN Package
• APPLICATIONS
  • Second-Level Protection in Li-Ion Battery Packs
    • Notebook Computers
    • Power Tools
    • Portable Equipment and Instrumentation

• Function
• Protection
• Number of series cells (Min)
• 2, 3, 4
• Number of series cells (Max)
• 3, 4
• Features
• Overvoltage, Single pin output drive
• Typical operating current (Typ) (uA)
• 2
• Rating
• Catalog
• Vin (Max) (V)
• 28

BQ29449的完整型号有：BQ29449DRBR、BQ29449DRBT，以下是这些产品的关键参数及官网采购报价：

BQ29449DRBR，工作温度：-40 to 85，封装：SON (DRB)-8，包装数量MPQ：3000个，MSL 等级/回流焊峰值温度：Level-2-260C-1 YEAR，引脚镀层/焊球材料：NIPDAU，TI官网BQ29449DRBR的批量USD价格：.909（1000+）

BQ29449DRBT，工作温度：-40 to 85，封装：SON (DRB)-8，包装数量MPQ：250个，MSL 等级/回流焊峰值温度：Level-2-260C-1 YEAR，引脚镀层/焊球材料：NIPDAU，TI官网BQ29449DRBT的批量USD价格：1.067（1000+）