| 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 |
- 2-Series, 3-Series, or 4-Series Cell Secondary Protection
- External Capacitor-Controlled Delay Timer
- Low Power Consumption ICC < 2μA 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
- Second-Level Protection in Li-Ion Battery Packs
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.