BQ27Z561 Impedance Track™ Gas Gauge Solution for 1-Series |


Impedance Track™ Gas Gauge Solution for 1-Series



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.


  • 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)

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Parametrics Compare all products in Battery fuel gauges

Number of series cells
Cell chemistry
Battery capacity (Max) (mAh)
Communication interface
Battery capacity (Min) (mAh)
External capacity indication
Gas gauge algorithm
Cell balancing
Operating temperature range (C)
Package Group
Package size: mm2:W x L (PKG)
BQ27Z561 BQ27542-G1 BQ27546-G1 BQ27742-G1 BQ27750
Single Cell     Single Cell     Single Cell     Single Cell     Single Cell    
Li-Ion/Li-Polymer     Li-Ion/Li-Polymer     Li-Ion/Li-Polymer     Li-Ion/Li-Polymer     Li-Ion/Li-Polymer
30000     32000     32000     16000     14000    
100     100     100     200     100    
None     None     None     None     None    
Pack     Pack     Pack     Pack     Pack    
Impedance Track     Impedance Track     Impedance Track     Impedance Track     Impedance Track    
SHA-256 Authentication     SHA-1 Authentication     SHA-1 Authentication     Integrated Protector
SHA-1 Authentication    
Accumulated Coulomb Count
Battery Management Unit
Integrated Protector
SHA-1 Authentication    
-40 to 85     -40 to 85     -40 to 85     -40 to 85     -40 to 85    
DSBGA | 12     SON | 12     DSBGA | 15     DSBGA | 15     SON | 12    
See datasheet (DSBGA)     See datasheet (SON)     See datasheet (DSBGA)     See datasheet (DSBGA)     See datasheet (SON)