SLUSC91D October 2015  – May 2016


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Supply Current
    6. 6.6 Digital Input and Output DC Characteristics
    7. 6.7 LDO Regulator, Wake-up, and Auto-Shutdown DC Characteristics
    8. 6.8 LDO Regulator, Wake-up, and Auto-Shutdown AC Characteristics
    9. 6.9 ADC (Temperature and Cell Measurement) Characteristics
    10. 6.10Integrating ADC (Coulomb Counter) Characteristics
    11. 6.11I2C-Compatible Interface Communication Timing Characteristics
    12. 6.12SHUTDOWN and WAKE-UP Timing
    13. 6.13Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1Communications
        1. Interface
        2. Time Out
        3. Command Waiting Time
        4. Clock Stretching
    4. 7.4Device Functional Modes
  8. Application and Implementation
    1. 8.1Application Information
    2. 8.2Typical Applications
      1. 8.2.1Design Requirements
      2. 8.2.2Detailed Design Procedure
        1. Voltage Sense Input
        2. LDO Capacitor
        3. Resistor Selection
      3. 8.2.3External Thermistor Support
      4. 8.2.4Application Curves
  9. Power Supply Recommendation
    1. 9.1Power Supply Decoupling
  10. 10Layout
    1. 10.1Layout Guidelines
    2. 10.2Layout Example
  11. 11Device and Documentation Support
    1. 11.1Documentation Support
      1. 11.1.1Related Documentation
    2. 11.2Community Resources
    3. 11.3Trademarks
    4. 11.4Electrostatic Discharge Caution
    5. 11.5Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Orderable Information


  • Single-Cell Li-Ion Battery Fuel Gauge
    • Resides on System Board
    • Supports Embedded or Removable Batteries
    • Powers Directly from the Battery with Integrated LDO
    • Supports a Low-Value External Sense Resistor (10 mΩ)
  • Ultra Low Power Consumption in NORMAL (50 µA) and SLEEP (9 µA) Modes
  • Battery Fuel Gauging Based on Patented Impedance Track™ Technology
    • Provides Three Selectable Pre-Programmed Profiles for 4.2-V, 4.35-V, and 4.4-V Cells
    • Reports Remaining Capacity and State-of-Charge (SOC) with Smoothing Filter
    • Adjusts Automatically for Battery Aging, Self-Discharge, Temperature, and Rate Changes
    • Estimates Battery State-of-Health (Aging)
  • Microcontroller Peripheral Interface Supports:
    • 400-kHz I2C™ Serial Interface
    • Configurable SOC Interrupt or
      Battery Low Digital Output Warning
    • Internal Temperature Sensor OR Host Reported Temperature OR External Thermistor


  • Smartphones, Feature Phones, and Tablets
  • Wearables
  • Building Automation
  • Portable Medical/Industrial Handsets
  • Portable Audio
  • Gaming


The Texas Instruments bq27426 battery fuel gauge is a single-cell gauge that requires minimal user-configuration and system microcontroller firmware development, leading to quick system bring-up.

Three chemistry profiles are pre-programmed to enable minimum user-configuration, and to help manage customer inventory across projects with different battery chemistries. The bq27426 battery fuel gauge has very low sleep power consumption leading to longer battery run time. Configurable interrupts help save system power and free up the host from continuous polling. Accurate temperature sensing is supported via an external thermistor.

The bq27426 battery fuel gauge uses the patented Impedance Track™ algorithm for fuel gauging, and provides information such as remaining battery capacity (mAh), state-of-charge (%), and battery voltage (mV).

Battery fuel gauging with the bq27426 fuel gauge requires connections only to PACK+ (P+) and PACK– (P–) for a removable battery pack or embedded battery circuit. The tiny, 9-ball, 1.62 mm x 1.58 mm, 0.5 mm pitch NanoFree™ chip scale package (DSBGA) is ideal for space-constrained applications.

Device Information(1)

bq27426YZF (9)1.62 mm x 1.58 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

bq27426 typ_app.gif

Revision History

Changes from C Revision (February 2016) to D Revision

Changes from B Revision (February 2016) to C Revision