BQ27Z561

• Supports current sense resistors down to 1 mΩ
• SHA-256 authentication responder for increased battery pack security
• Two independent ADCs
  • Support for simultaneous current and voltage sampling
  • High-accuracy coulomb counter with input offset error < 1 µV (typical)
• Low-voltage (2 V) operation
• Supports pack-side gauging
• Wide-range current applications (1 mA to > 5 A)
• Active high or low interrupt pin
• Reduced power modes (typical battery pack operating range conditions)
  • Typical SLEEP mode: < 11 µA
  • Typical DEEP SLEEP mode: < 9 µA
  • Typical OFF mode: < 1.9 µA
• Internal and external temperature sense functions
• 400-kHz I²C bus communications interface for high-speed programming and data access
• HDQ one-wire for communication with host
• Compact 12-pin DSBGA package (YPH)

The Texas Instruments BQ27Z561 Impedance Track™ gas gauge solution is a highly integrated, accurate 1-series cell gas gauge with a flash programmable custom reduced instruction-set CPU (RISC) and SHA-256 authentication for Li-Ion and Li-Polymer battery packs. The 1-series cell capability includes parallel cells for increased capacity.

The BQ27Z561 gas gauge communicates via I²C-compatible and HDQ one-wire interfaces and includes several key features that can help facilitate accurate gas gauging applications. Integrated temperature sense functions (internal and external options) enable system and battery temperature measurements. The integrated SHA-256 functionality helps enable secure identification between systems and packs. The interrupt function facilitates the BQ27Z561 device to inform the system when a state-of-charge (SOC), voltage, or temperature fault occurs. The low-voltage operation enables the system to continue monitoring the battery even in deeply discharged conditions. During low-activity situations, the device can be set to the low power coulomb counting (CC) mode, which allows the device to continue its coulomb counting while reducing operating current significantly.