1 Features

1• Single-Cell Li-Ion Battery Fuel Gauge

– Resides on System Board

– Supports Embedded or Removable Batteries

– Powered Directly from Battery with Integrated

LDO

– Low-Value Integrated Sense Resistor

(7 mΩ, Typical)

• Easy-to-Configure Fuel Gauging Based on

Patented Impedance Track™ Technology

– Reports Remaining Capacity and State-of-

Charge (SOC) with Smoothing Filter

– Automatically Adjusts for Battery Aging, Self-

Discharge, Temperature, and Rate Changes

– Battery State-of-Health (Aging) Estimation

• Microcontroller Peripheral Supports:

– 400-kHz I2C Serial Interface

– Configurable SOC Interrupt or

Battery Low Digital Output Warning

– Internal Temperature Sensor or

Host-Reported Temperature

2 Applications

• Smartphones, Feature Phones, and Tablets

• Digital Still and Video Cameras

• Handheld Terminals

• MP3 or Multimedia Players

3 Description

The Texas Instruments bq27421-G1 fuel gauge is a

minimally configured microcontroller peripheral that provides system-side fuel gauging for single-cell Li-

Ion batteries. The device requires very little user

configuration and system microcontroller firmware

development.

The bq27421-G1 fuel gauge uses the patented

Impedance TrackTM algorithm for fuel gauging, and

provides information such as remaining battery

capacity (mAh), state-of-charge (%), and battery voltage (mV).

Battery fuel gauging with the bq27421-G1 fuel gauge requires connections only to PACK+ (P+) and PACK–

(P–) for a removable battery pack or embedded

battery circuit. The tiny 9-ball, 1.62 mm × 1.58 mm,

0.5-mm pitch NanoFree™ chip scale package

(DSBGA) is ideal for space-constrained applications.