Not Recommended for New Designs
bq27505-J3
www.ti.com
SLUS986A–OCTOBER 2009–REVISED FEBRUARY 2010
System-Side Impedance Track™ Fuel Gauge
1 INTRODUCTION
1.1 FEATURES
1.2 APPLICATIONS
123
• Battery Fuel Gauge for 1-Series Li-Ion
•
•
•
•
•
Smartphones
Applications
• Resides on System Main Board
PDAs
Digital Still and Video Cameras
Handheld Terminals
MP3 or Multimedia Players
– Works With Embedded or Removable
Battery Packs
• Uses PACK+, PACK–, and T Battery Terminals
• Microcontroller Peripheral Provides:
– Accurate Battery Fuel Gauging
1.3 DESCRIPTION
– 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
The Texas Instruments bq27505 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
resides on the system’s main board and manages an
embedded battery (non-removable) or a removable
battery pack.
– 96 Bytes of Non-Volatile Scratch-Pad FLASH
• Battery Fuel Gauge Based on Patented
Impedance Track™ Technology
The bq27505 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 (%).
– Models the Battery Discharge Curve for
Accurate Time-to-Empty Predictions
– Automatically Adjusts for Battery Aging,
Battery Self-Discharge, and
Temperature/Rate Inefficiencies
Battery fuel gauging with the bq27505 requires only
PACK+ (P+), PACK– (P–), and Thermistor (T)
– Low-Value Sense Resistor (10 mΩ or Less)
• 400-kHz I2C™ Interface for Connection to
System Microcontroller Port
connections to
a
removable battery pack or
embedded battery circuit. The CSP option is a 12-ball
package in the dimensions of 2,43 mm × 1,96 mm
with 0,5 mm lead pitch. It is ideal for space
constrained applications.
• In a 12-Pin NanoFree™ (CSP) Packaging
TYPICAL APPLICATION
Host System
LDO
Single Cell Li-lon
Battery Pack
VCC
Voltage
Sense
PACK+
PROTECTION
IC
Battery
Low
Temp
Sense
I2C
DATA
T
Power
Management
Controller
bq27505
CHG
DSG
PACK-
FETs
BAT_GD
SOC_INT
Current
Sense
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Impedance Track, NanoFree are trademarks of Texas Instruments.
2
3
I2C is a trademark of Philips Electronics.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2009–2010, Texas Instruments Incorporated