BQ28Z560-R1_14 Datasheet, PDF (46/61 Pages) Texas Instruments – Single Cell Li-Ion Battery Gas Gauge

bq28z560-R1
Not Recommended For New Designs
SLUSBD3 – APRIL 2013
www.ti.com
Because the gas gauge is dormant in HIBERNATE mode, the battery should not be charged or discharged in this
mode, because any changes in battery charge status will not be measured. If necessary, the host equipment can
draw a small current (generally infrequent and less than 1 mA, for purposes of low-level monitoring and
updating); however, the corresponding charge drawn from the battery will not be logged by the gauge. Once the
gauge exits to NORMAL mode, the algorithm re-establishes the correct battery capacity.
If a charger is attached, the host should immediately take the gas gauge out of HIBERNATE mode before
beginning to charge the battery.
CAUTION
Charging the battery in HIBERNATE mode results in a notable gauging error that will
take several hours to correct. In the HDQ bus communication interface, the bus line,
when in HIBERNATE mode, must always be pulled high with an external resistor, and
not allowed to go low in this mode. If the bus line is pulled low, the system may need
to go through a full reset by the battery pack being removed and re-inserted. This may
be an issue for systems with embedded battery packs. Alternatively, disable
HIBERNATE mode by setting the CLEAR HIBERNATE bit to 0. Another option is to set
Hibernate I,V settings to 0 in DF commands.
SHUTDOWN MODE
The device enters SHUTDOWN mode if there is a BATLOW condition detected or power down of the system.
The device can also disable SHUTDOWN by using the CLEAR_SHUTDOWN (0x0014) option.
NOTE
• A SHUTDOWN command should NOT be invoked if charger voltage is present.
• Sending a SHUTDOWN command while charger voltage is present causes a 1–2 s
time of DSG FET off, and may or may not cause a watchdog reset. (If current is ≤ 0
after the DSG FET is opened, it will attempt to shutdown and start a watchdog;
otherwise, it will only clear the shutdown flag without a reset.)
• The recommendation is to NOT send a SHUTDOWN command if charger voltage is
present.
Figure 8 shows an overview of the hardware controlled SHUTDOWN operation.
46
Submit Documentation Feedback
Product Folder Links: bq28z560-R1
Copyright © 2013, Texas Instruments Incorporated