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

特性 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.