TI BQ29209DRBR

The bq2920x device is a secondary overvoltage protection integrated circuit (IC) for 2-series lithium-ion battery packs. It integrates a high-precision overvoltage detection circuit and an automatic charge imbalance correction function. This IC compares the voltage of each cell in the 2-series battery pack with the factory-set internal reference voltage. If any cell reaches an overvoltage state, the OUT pin transitions from a low-level to a high-level state. The bq2920x can perform voltage-based automatic charge imbalance correction. Charge balancing starts when the battery voltage differs from the internal reference voltage by 30mV (nominal) or more and stops when the difference is 0mV (nominal). The charge balancing function is enabled and disabled via the CB_EN pin.

• 2-cell series battery secondary protection
• Automatic cell balancing with external enable control
• ±30mV enable threshold, 0mV disable threshold (typical)
• External capacitor-controlled delay timer
• External resistor-controlled cell balancing current
• Low power |cc<3|A (typical) (VCELL (total voltage) < VPROTECT)
• Internal cell balancing supports up to 15mA
• External cell balancing mode support
• High-accuracy overvoltage protection: ±25mV (ΔTA = 0°C to 60°C)
• Fixed overvoltage protection thresholds: 4.30V, 4.35V
• Small 8-pin DRB package

• Secondary protection for Li-ion battery packs
• Laptop computers
• Power tools
• Portable devices and instruments
• Backup battery systems