TI Unveils Battery Management Chips
Texas Instruments today introduced several new battery management integrated circuits (ICs), including its next-generation Impedance Track(TM) “gas gauge” chipset, to improve battery performance and protect multi-cell, lithium-based battery packs used in notebooks and other systems.
Texas Instruments Incorporated (NYSE: TXN – News; TI) today introduced
several new battery management integrated circuits (ICs), including its
next-generation Impedance Track(TM) "gas gauge" chipset, to improve battery
performance and protect multi-cell, lithium-based battery packs used in
notebooks and other systems.
Next-Generation Impedance Track Gas Gauge
TI’s bq20z90 next-generation Impedance Track battery gas gauge chipset, which
integrates new state-of-the-art battery authentication technology, is designed
to work with TI’s newest analog front end (AFE) protection IC. Requiring a third
fewer components than its predecessor, the 99-percent accurate bq20z90 chipset
was designed with ease-of-use and smallest real estate in mind. The gas gauge
closely monitors battery capacity, impedance, cell balance, open-circuit voltage
and other critical parameters of a 7.2-V, 10.8-V or 14.4-V battery pack and
reports the information to the system host controller over a
serial-communication bus. See: http://www.ti.com/sc06160 .
TI’s Impedance Track gas gauge technology, launched in 2004 with the bq20z80
chipset, precisely measures changes in impedance, or resistance caused by
battery age, temperature and cycle life, to accurately predict run-time of
battery packs with two, three and four cells in series. An exact "starting
position" is determined for instant state-of-charge, and total capacity is
calculated from the amount of capacity that exists, which eliminates the need
for a full-charge and discharge cycle.
The bq20z90 drives a three-, four- or five-segment LED display for remaining
capacity indication. For those designs that do not require the display
indicator, TI also introduced its bq20z70 gas gauge chipset without the LED
Front-End Battery Protection
The bq20z90 is designed to work with TI’s new bq29330 AFE protection circuit
with two integrated linear dropout regulators (LDOs) to further maximize
functionality and reduce external component count. The device utilizes an I2C
communications interface to allow the bq20z90 to monitor safety battery
conditions such as voltage, individual cell voltages and cell- balancing data,
and report the information to the host system. See: http://www.ti.com/sc06160b .
A designer can program critical safety parameters such as current protection
thresholds and delays into the bq29330 to increase flexibility of the battery
management system. The device also provides protection for overload
short-circuit in charge and discharge conditions, while providing battery cell
over-voltage and under-voltage protection.
Integrated SHA-1 Based Authentication
The bq20z90 integrates SHA-1, 128-bit decryption functionality, which easily
identifies potentially unsafe batteries not approved by original equipment
manufacturers for use in their devices. If the battery information checks out,
the system can allow normal system operation with the battery pack. A
manufacturer can program the system to take action to protect the consumer if
the battery pack response is not correct, or if the battery pack is not approved
or determined to be defective. In addition, TI introduced a bq26100 protection
device for those designers who prefer a discrete implementation of the SHA-1
protection feature. See: http://www.ti.com/sc06160c .
Smart Battery Test Board
In addition to the new battery gas gauge chipset, TI has developed a unique
development platform aimed at battery pack suppliers. TI’s new bqMTester smart
battery development board simplifies production of battery modules at a fraction
of the cost. bqMTester eliminates the need for an onboard computer and expensive
calibration/traceable power supplies and electronic loads. It calibrates and
programs electronic smart battery modules based on advanced battery fuel gauges,
such as the bq20z90, bq20z80 and bq20z70 devices with Impedance Track. In
addition, bqMTester makes tracking battery modules in production easier by
programming serial number, date, pack lot code and other defaults. The bqMTester
board can be ordered at http://www.ti.com/bqmtester .
Pricing and Availability
The bq20z90 and bq20z70 gas gauge chipsets, bq29330 protection AFE and bq26100
authentication circuit are available in volume production from TI and its
authorized distributors. The bq20z90 is packaged in a 30-pin thin shrink small
outline package (TSSOP), the smaller bq29z70 in a 20-pin TSSOP, the bq29330 in a
30-pin TSSOP package and the bq26100 in a tiny, 6-pin SON package. Suggested
resale pricing in 1,000 piece quantities is $ 3.30 for the bq20z90, $ 2.90 for the
bq20z70, $ 1.45 for the bq29330, and $ 1.30 for the bq26100.
Evaluation modules for the bq20z90 gas gauge chipset, the bqMTester development
board, reference designs, application notes and technical documentation are
available through http://www.ti.com/impedancetrack .