BQ20Z80 SBS 1.1-Compliant Gas Gauge Enabled with Impedance Track™ Technology for Use With the bq29312 |

BQ20Z80 (NRND)

SBS 1.1-Compliant Gas Gauge Enabled with Impedance Track™ Technology for Use With the bq29312


Not Recommended for New Designs (NRND)

Replaced By BQ40Z50-R2 – The device has SIMILAR FUNCTIONALITY but is not functionally equivalent to the compared device.

TI does not recommend using this part in a new design. This product continues to be in production to support existing customers.


The bq20z80 SBS-compliant gas gauge IC, incorporating patented Impedance Track™ technology, is designed for battery-pack or in-system installation. The bq20z80 measures and maintains an accurate record of available charge in Li-ion or Li-polymer batteries using its integrated high-performance analog peripherals. The bq20z80 monitors capacity change, battery impedance, open-circuit voltage, and other critical parameters of the battery pack, and reports the information to the system host controller over a serial-communication bus. It is designed to work with the bq29312A analog front-end (AFE) protection IC to maximize functionality and safety, and minimize component count and cost in smart battery circuits.

The Impedance Track technology continuously analyzes the battery impedance, resulting in superior gas-gauging accuracy. This enables remaining capacity to be calculated with discharge rate, temperature, and cell aging all accounted for during each stage of every cycle.


  • Patented Impedance Track™ Technology Accurately Measures Available Charge in Li-Ion and Li-Polymer Batteries
  • Better than 1% Error Over Lifetime of the Battery
  • Instant Accuracy – No Learning Cycle Required
  • Supports the Smart Battery Specification SBS V1.1
  • Works With the TI bq29312A Analog Front-End (AFE) Protection IC to Provide Complete Pack Electronics Solution
  • Full Array of Programmable Voltage, Current, and Temperature Protection Features
  • Integrated Time Base Removes Need for External Crystal with Optional Crystal Input
  • Electronics for 7.2-V, 10.8-V or 14.4-V Battery Packs With Few External Components
  • Based on a Powerful Low-Power RISC CPU Core With High-Performance Peripherals
  • Integrated Field Programmable FLASH Memory Eliminates the Need for External Configuration Memory
  • Measures Charge Flow Using a High-Resolution, 16-Bit Integrating Delta-Sigma Converter
    • Better Than 0.65 nVh of Resolution
    • Self-Calibrating
    • Offset Error Less Than 1 µV
  • Uses 16-Bit Delta-Sigma Converter for Accurate Voltage and Temperature Measurements
  • Extensive Data Reporting Options For Improved System Interaction
  • Optional Pulse Charging Feature for Improved Charge Times
  • Drives 3-, 4- or 5-Segment LED Display for Remaining Capacity Indication
  • Supports SHA-1 Authentication
  • Lifetime Data Logging
  • 38-Pin TSSOP (DBT)
    • Notebook PCs
    • Medical and Test Equipment
    • Portable Instrumentation

Impedance Track is a trademark of Texas Instruments.