BQ20Z45 SBS 1.1 compliant Gas Gauge with Impedance Track Technology and Advanced Charging Algorithm |

BQ20Z45 (NRND) SBS 1.1 compliant Gas Gauge with Impedance Track Technology and Advanced Charging Algorithm


Not Recommended for New Designs (NRND)

Replaced By BQ20Z45-R1 – The device is an EXACT EQUIVALENT in functionality and parametrics 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 bq20z45 SBS-compliant gas gauge and protection IC is a single IC solution designed for battery-pack or in-system installation. The bq20z45 measures and maintains an accurate record of available charge in Li-ion or Li-polymer batteries using its integrated high-performance analog peripherals, monitors capacity change, battery impedance, open-circuit voltage, and other critical parameters of the battery pack as well and reports the information to the system host controller over a serial-communication bus. Together with the integrated analog front-end (AFE) short-circuit and overload protection, the bq20z45 maximizes functionality and safety while minimizing external component count, cost, and size in smart battery circuits.

The implemented Impedance Track™ gas gauging 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 with high accuracy.


  • Next Generation Patented Impedance Track™ Technology Accurately Measures Available Charge in Li-Ion and Li-Polymer Batteries
    • Better Than 1% Error Over the Lifetime of the Battery
  • Supports the Smart Battery Specification SBS V1.1
  • Flexible Configuration for 2 to 4 Series Li-Ion and Li-Polymer Cells
  • Powerful 8-Bit RISC CPU With Ultralow Power Modes
  • Full Array of Programmable Protection Features
    • Voltage, Current, and Temperature
  • Satisfies JEITA Guidelines
  • Added Flexibility to Handle More Complex Charging Profiles
  • Lifetime Data Logging
  • Supports SHA-1 Authentication
  • Complete Battery Protection and Gas Gauge Solution in One Package
  • Available in a 38-Pin TSSOP (DBT) package
    • Notebook PCs
    • Medical and Test Equipment
    • Portable Instrumentation

Impedance Track is a trademark of Texas Instruments.