BQ27350 Datasheet, PDF (1/33 Pages) Texas Instruments – Single Cell Li-Ion Battery Manager With Impedance Track Fuel Gauge Technology

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1 INTRODUCTION
1.1 FEATURES
• Comprehensive Battery Fuel Gauge for Single
Cell and 1-Series Li-Ion Applications
• Secure Battery Authentication Using
SHA-1/HMAC Encryption
• Calculates and Reports
– Remaining Battery Capacity
– Battery Voltage and Temperature
– Charge and Discharge Current
– Four Time-to-Empty Predictions
• 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 (10mΩ or Less)
• 96-Bytes Non-Volatile Scratch Pad Data
Memory
• I²C Communications Interface to the Host
• 20-Pin TSSOP Package
bq27350
Single Cell Li-Ion Battery Manager
With Impedance Track Fuel Gauge Technology
SLUS754 – MARCH 2007
1.2 APPLICATIONS
• POS Terminals
• Industrial Data Collection
• Smartphones
• PDAs
• Digital Cameras
• Handheld Terminals
1.3 DESCRIPTION
The Texas Instruments’ bq27350 is a battery fuel
gauge with secure authentication support for single
cell Li-Ion battery packs. Designed for battery pack
integration, the device requires little host
microcontroller firmware support for implementation.
The system host processor communicates with the
bq27350 over an I²C interface to obtain remaining
battery capacity, system run-time predictions, and
other critical battery information.
The bq27350 uses the patented Impedance Track™
algorithm for its fuel gauging. The gauge provides
information such as state-of-charge (%), run-time to
empty (min.), charge time to full (min.), battery
voltage (V), and pack temperature (°C).
The bq27350 also features both integrated and
external support for secure battery pack
authentication, using the SHA-1/HMAC authentication
algorithm.
PACK+
SCLK
SDATA
Single-Cell
Protector
PACK-
TYPICAL IMPLEMENTATION
bq27350
Impedance Track™
SHA-1/HMAC
Authentication and
Manufacturing
Data Storage
*
LDO
bq26100
SHA-1/HMAC
Authentication
(optional)
*Optional Thermistor
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.
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, Texas Instruments Incorporated