1FEATURES

2• 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

• Available in a 20-Pin TSSOP (PW) package

APPLICATIONS

• Notebook PCs

• Medical and Test Equipment

• Portable Instrumentation

DESCRIPTION

The bq20z40 SBS-compliant gas gauge and

protection IC, incorporating patented Impedance

Track™ technology, is designed for battery-pack or

in-system installation. The bq20z40 measures and

maintains an accurate record of available charge in

Li-ion or Li-polymer batteries using its integrated

high-performance analog peripherals. The bq20z40

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 bq29330 analog

front-end (AFE) protection IC to maximizes

functionality and safety while minimizing external

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 the remaining

capacity to be calculated with discharge rate,

temperature, and cell aging that are all accounted for

during each stage of every cycle.