BQ20Z655

• 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-Series to 4-Series Li-Ion and Li-Polymer Cells
• Powerful 8-Bit RISC CPU with Ultralow Power Modes
• Charge Enable (CE) Affects the Normal Operation on the Charge FET when
  the Battery Is in Charge/Relax Mode
• Full Array of Programmable Protection Features
  • Voltage, Current, and Temperature
• Satisfies JEITA Guidelines
• Added Flexibility to Handle More Complex Charging Profiles
• Lifetime Data Logging
• Drives 3, 4, or 5 Segment Liquid Crystal Display and LED for
  Battery-Pack Conditions
• Supports SHA-1 Authentication
• Complete Battery Protection and Gas Gauge Solution in One Package
• Available in a 44-Pin TSSOP (DBT) Package

The bq20z655 SBS-compliant gas gauge and protection IC, incorporating patented Impedance Track™ technology, is a single IC solution designed for battery-pack or in-system installation. The bq20z655 measures and maintains an accurate record of available charge in Li-Ion or Li-Polymer batteries using its integrated high-performance analog peripherals. The bq20z655 monitors capacity change, battery impedance, open-circuit voltage, and other critical parameters of the battery pack which 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 bq20z655 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.