BQ20Z80-V102_07 Datasheet, PDF (24/28 Pages) Texas Instruments – SBS 1.1-COMPLIANT GAS GAUGE ENABLED WITH IMPEDANCE TRACK TM TECHNOLOGY FOR USE WITH THE BQ29312A

bq20z80-V102
SLUS681B – NOVEMBER 2005 – REVISED JANUARY 2007
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CHANGE
bq20z80
bq20z80-V101
COMMENTS
Improved thermal model
A preliminary thermal mode was
used.
An updated thermal model is used.
Improved thermal compensation of
Impedance Track™ algorithm
Improved cell capacity measurement
by limiting valid temperature ranges
Valid voltage measurements for cell
capacity estimation can occur at any
temperature.
Valid voltage measurements for cell Improves capacity estimation
capacity estimation must occur within
a defined temperature range.
Improved cell capacity measurement
After a full reset, it may take several
minutes for voltage reading to settle
to the most accurate reading.
Settling time of voltage
measurements after a full reset is
reduced.
Improves initial voltage reading
accuracy
Improved default resistance tables
A preliminary default resistance mode An updated default resistance mode Improved thermal accuracy of
was used.
is used.
Impedance Track™ algorithm
Prevented lifetime updates until IT is Data flash lifetime data is updated
enabled
under all conditions.
Data flash lifetime data is not updated Improves suitability of lifetime data
until Impedance Track™ is enabled.
Aligned SBS.RemainingCapacity( )
with DF:Terminate Voltage
SBS.RemainingCapacity( ) could be
above zero when SBS.Voltage( )
reaches DF:Terminate Voltage.
Forces SBS.RemainingCapacity( ) to
zero when SBS.Voltage( ) is below
terminate voltage
Improves alignment between
reporting and system status
Disabled LEDs for undervoltage
conditions
When SBS.OperationStatus( ) [CUV
or PUV] is set, then the LED display
could be activated.
When SBS.OperationStatus( ) [CUV
or PUV] is set, the LED display is
disabled.
Reduces risk of deeply discharging
the battery
Clear SBS.BatteryStatus( ) [RCA]
SBS.BatteryStatus( ) [RCA] is not
when not SBS.BatteryStatus( ) [DSG] cleared when SBS.BatteryStatus( )
[DSG] is cleared.
SBS.BatteryStatus( ) [RCA] is now
cleared when SBS.BatteryStatus( )
[DSG] is cleared.
Corrected to meet SBS specification
Allowed sleep mode for undervoltage When SBS.OperationStatus( ) [CUV
conditions
or PUV] is set, then entry to sleep
mode is disabled.
When SBS.OperationStatus( ) [CUV
or PUV] is set, then entry to sleep
mode is allowed.
Reduces risk of deeply discharging
the battery
Improvements made to Lifetime data
Does not save maximum and
minimum lifetime AverageCurrent or
AveragePower. Only saves lifetime
data when new values exceed old
values by defined delta values
Saves maximum and minimum
lifetime AverageCurrent and
AveragePower. Lifetime data is saved
after a defined period of time even if
new values do not exceed old values
by defined delta values
Improves lifetime data
Changes made to pulse charging
Voltages for pulse charging are
sampled once a second.
Voltages for pulse charging are
sampled 4 times a second.
Improves pulse charging
Changes made to charging timeouts
The precharge timeout timer runs
when the charging current is below a
defined threshold; so, it is possible
that the precharge timer will run
during charging taper current and
cause an undesired precharge
timeout during charging taper.
The fast charge and precharge
timeout timers only run when
precharging or charging, as indicated
by FCHG and PCHG bits in
ChargingStatus.
Improves operation of fast charge and
precharge timeout timers
Changes made to discharge faults
Discharging fault is indicated
whenever BatteryStatus [TDA] is set.
Current discharging fault is not
indicated for current faults detect by
AFE. Separate discharging faults are
indicated for voltage and temperature.
Discharging fault is indicated for any
safety condition resulting in turning off
the discharge FET. Current
discharging fault is indicated for all
detected overcurrent conditions,
including overcurrent detected by
AFE. Temperature and voltage
discharge faults are not indicated
separately.
Improves indication of discharging
fault conditions
Improvements made to calibration
functions
Voltage calibration functions may
cause error in voltage calibration of
several millivolts.
Voltage calibration functions are
Improved voltage calibration accuracy
capable of accuracy within 1 millivolt.
Protect against simultaneous writes to
data flash
A SMBus-initiated data flash write
may occur at the same time as a data
flash write initiated by the AGG, which
my cause a data flash write error.
A SMBus-initiated data flash write
cannot occur at the same time as any
other data flash write.
Increased robustness of data flash
writes
Corrected
SBS.ManufacturerAccess( ) access of SBS.ManufacturerAccess( ) access of Allows host to determine bq20z80
SBS.ManufacturerAccess( ) access of silicon revision is not functional.
silicon revision is functional.
silicon revision
silicon revision
Corrected data flash checksum
operation
The data flash checksum includes
non-accessible portions of the data
flash that change when writing the
data flash checksum, invalidating the
checksum.
The data flash checksum only
includes data flash that does not
change when writing an updated data
flash checksum.
Data flash checksum operation works
correctly.
Corrections made to LED display
Fixed LED thresholds cannot be
selected.
Fixed LED thresholds can be
selected.
Correct operation of LED threshold
settings
Erroneous readings are corrected that
occurred after offset calibration when
sleep mode is not entered.
Erroneous SBS voltage, current, and
temperature readings occur after
current offset calibration if sleep mode
is not entered, corrupting the lifetime
data.
No erroneous SBS voltage, current,
and temperature readings occur after
current offset calibration if sleep mode
is not entered.
Improve reliability of lifetime data
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