1 INTRODUCTION

1.1 FEATURES

123? Battery Fuel Gauge for 1-Series Li-Ion

Applications

? Resides on System Main Board

– Works With Embedded or Removable

Battery Packs

? Microcontroller Peripheral Provides:

– Accurate Battery Fuel Gauging

– Internal Temperature Sensor for Battery

Temperature Reporting

– Battery Low Interrupt Warning

– Battery Insertion Indicator

– Configurable Level of State of Charge (SOC)

Interrupts

– State of Health Indicator

– 96 Bytes of Non-Volatile Scratch-Pad FLASH

? Battery Fuel Gauge Based on Patented

Impedance Track? Technology

– Models the Battery Discharge Curve for

Accurate Time-to-Empty Predictions

– Automatically Adjusts for Battery Aging, Battery Self-Discharge, and

Temperature/Rate Inefficiencies

– Low-Value Sense Resistor (10 mΩ or Less)

? 400-kHz I2C? Interface for Connection to

System Microcontroller Port

? In a 12-Pin NanoFree? (CSP) Packaging

1.2 APPLICATIONS

? Smartphones and PDAs

? Digital Still and Video Cameras

? Handheld Terminals

? MP3 or Multimedia Players

1.3 DESCRIPTION

The Texas Instruments bq27505-J4

system-side Li-Ion battery fuel gauge is a

microcontroller peripheral that provides fuel

gauging for single-cell Li-Ion battery packs.

The device requires little system

micro-controller firmware development. The

bq27505-J4 resides on the system’s main

board and manages an embedded battery

(nonremovable) or a removable battery pack.

The bq27505-J4 uses the patented Impedance

Track algorithm for fuel gauging, and provides

information such as remaining battery capacity

(mAh), state-of-charge (%), run-time to empty

(min), battery voltage (mV), temperature (°C)

and state of health(%).

Battery fuel gauging with the bq27505-J4

requires only PACK+ (P+), PACK– (P–), and

Thermistor (T) connections to a removable

battery pack or embedded battery circuit. The

CSP option is a 12-ball package in the

dimensions of 2.43mm × 1.96mm with 0.5mm

lead pitch. It is ideal for space constrained

applications.