BQ29449 Series
Secondary Over-Voltage Protection for 2-4 cell in series Li-Ion/Poly (4.30V)
Manufacturer: Texas Instruments
Catalog
Secondary Over-Voltage Protection for 2-4 cell in series Li-Ion/Poly (4.30V)
Key Features
• 2-Series, 3-Series, or 4-Series Cell Secondary ProtectionExternal Capacitor-Controlled Delay TimerLow Power Consumption ICC< 2 µA Typical[VCELL(ALL) < VPROTECT]High-Accuracy Overvoltage Protection:±25 mV with TA= 0°C to 60°CFixed Overvoltage Protection Thresholds:4.30 V, 4.35 V, 4.40 V, 4.45 V, 4.50 VSmall 8L QFN PackageAPPLICATIONSSecond-Level Protection in Li-Ion Battery PacksNotebook ComputersPower ToolsPortable Equipment and Instrumentation2-Series, 3-Series, or 4-Series Cell Secondary ProtectionExternal Capacitor-Controlled Delay TimerLow Power Consumption ICC< 2 µA Typical[VCELL(ALL) < VPROTECT]High-Accuracy Overvoltage Protection:±25 mV with TA= 0°C to 60°CFixed Overvoltage Protection Thresholds:4.30 V, 4.35 V, 4.40 V, 4.45 V, 4.50 VSmall 8L QFN PackageAPPLICATIONSSecond-Level Protection in Li-Ion Battery PacksNotebook ComputersPower ToolsPortable Equipment and Instrumentation
Description
AI
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.
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.