BQ28Z560-R1 Datasheet, PDF (49/60 Pages) Texas Instruments – Single Cell Li-Ion Battery Gas Gauge and Protection

bq28z560-R1
www.ti.com
Mode
HIBERNATE
SHUTDOWN
SLUSBD3 – APRIL 2013
Enter Mode
Exit Mode
Comment
From FULLSLEEP mode, the
system will go into HIBERNATE
mode if the load current decreases
to programmed value,
OR if the cell voltage falls below the
programmed value,
OR if the host sets the command in
MAC.
The system exits this mode if the V_BAT
> programmed threshold,
OR load current is > programmed
threshold,
OR communication activity is on the
bus line,
OR the host sets the command in
MAC.
Enters hibernation if V_BAT range is
2.4 V to 3 V with a default at 2.55 V.
The load current threshold range is 0
to 0.7 A with a default value of 8 mA.
From SLEEP mode, the system will
enter this mode if the V_BAT < 2.4 V
for a period longer than 24 ms and
the charger is not attached. The
system can also be put in
SHUTDOWN mode through MAC.
Exit from this mode if there is bus
activity,
OR the load current detected is >
I_WAKE,
OR the charger is connected to the
system.
In this mode, the VREG and DSG
FET are turned OFF and the system
will only wake up if the charger is
attached on the Pack+, Pack–
terminals.
AUTOCALIBRATION
The bq28z560-R1 provides an auto calibration feature that measures the voltage offset error across SRP and
SRN from time-to-time as operating conditions change. It subtracts the resulting offset error from the normal
sense resistor voltage, VSR, for maximum measurement accuracy.
Auto calibration of the ADC begins on entry to SLEEP mode, except if Temperature() is ≤ 5°C or Temperature() ≥
45°C.
The gas gauge also performs a single offset when (1) the condition of AverageCurrent() ≤ 100 mA and (2) {cell
voltage change since last offset calibration ≥ 256 mV} or {temperature change since last offset calibration is
greater than 80°C for ≥ 60 s}.
Capacity and current measurements continue at the last measured rate during the offset calibration when these
measurements cannot be performed. If the battery voltage drops more than 32 mV during the offset calibration,
the load current has likely increased considerably and the offset calibration will be aborted.
Copyright © 2013, Texas Instruments Incorporated
Product Folder Links: bq28z560-R1
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