BQ27500_08 Datasheet, PDF (1/39 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge

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1 INTRODUCTION
bq27500
bq27501
System-Side Impedance Track™ Fuel Gauge
SLUS785D – SEPTEMBER 2007 – REVISED APRIL 2008
1.1 FEATURES
• Battery Fuel Gauge for 1-Series Li-Ion
Applications
• Resides on System Main Board
– Works With Embedded or Removable
Battery Packs
• Two Varieties
– bq27500: Uses PACK+, PACK–, and T
Battery Terminals
– bq27501: Works With Battery ID Resistor in
Battery Pack
• Microcontroller Peripheral Provides:
– Accurate Battery Fuel Gauging
– Internal Temperature Sensor for System
Temperature Reporting
– Battery Low Interrupt Warning
– Battery Insertion Indicator
– Battery ID Detection
– 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)
• I²C™ Interface for Connection to System
Microcontroller Port
• 12-Pin 2,5-mm × 4-mm SON Package
1.2 APPLICATIONS
• Smartphones
• PDAs
• Digital Still and Video Cameras
• Handheld Terminals
• MP3 or Multimedia Players
1.3 DESCRIPTION
The Texas Instruments bq27500/01 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
microcontroller firmware development. The
bq27500/01 resides on the system main board, and
manages an embedded battery (non-removable) or a
removable battery pack.
The bq27500/01 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), and temperature (°C).
Battery fuel gauging with the bq27500 requires only
PACK+ (P+), PACK– (P–), and Thermistor (T)
connections to a removable battery pack or
embedded battery. The bq27501 works with
identification resistors in battery packs to gauge
batteries of different fundamental chemistries and/or
significantly different rated capacities.
TYPICAL APPLICATION
Power
Management
Controller
Host System
LDO
Voltage
Battery
Low
Warning
Sense
RID
Sense*
Temp
I²C
Sense
bq27500/1
Battery
Good
Current
Sense
PACK+
RID
T
PACK–
Single-Cell Li-Ion
Battery Pack
Protection
IC
FETs
CHG
DSG
*bq27501 Only
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 document.
Impedance Track is a trademark of Texas Instruments.
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 © 2007–2008, Texas Instruments Incorporated