BQ27210 Datasheet, PDF (24/30 Pages) Texas Instruments – Li-Ion AND Li-Pol BATTERY GAS GAUGE IC FOR PORTABLE APPLICATIONS (bqJUNIOR)

bq27010, bq27210
SLUS707B – APRIL 2006 – REVISED JANUARY 2007
www.ti.com
Sleep Mode
This low power mode is entered when the HDQ or CLK and/or DTA line is pulled low for at least 18 seconds and
the charge or discharge activity is below the DMF threshold. Normal gas gauging ceases, but battery
self-discharge, based on the temperature when the device entered sleep mode, is maintained internally. The
device wakes every 43.6 minutes to update the temperature measurement and goes back to sleep after about
18 seconds if the HDQ or CLK and/or DTA line is still low and the charge or discharge activity is still below the
DMF threshold. The bqJUNIOR has an internal 3 µA pulldown current on each communication line, eliminating
the need to add external pulldown resistors to force a logic 0 on open communication lines.
When the device wakes, it stays in active mode long enough to confirm that the charge or discharge activity is
still below the digital magnitude filter threshold. This is meant to minimize possible error if the battery pack is
removed from the end equipment for a short period of time and then reinserted, and there is not a transient on
the communication lines to pull the device into the active mode. This is an issue only if the system has some
current drain from the battery even though the communication lines are low. The gauge reenters sleep mode
when the charge or discharge activity falls below the digital magnitude filter threshold.
When all communication lines are pulled high, the device leaves the sleep mode. If the DMF threshold is set to
zero and a communication line is pulled low, the device does not enter sleep mode until the average current
value is less than 3.57 µV/Rsr.
If the battery pack can be removed and placed on an external charger, the charger should have a pull-up
resistor on the HDQ or SCL and SDA lines to wake the part from sleep. A 100 kΩ pullup resistor from
communication line(s) to V_CC can be added in the battery pack to disable the sleep function.
Ship Mode (bq27010 only)
This low power mode is to be used when the pack manufacturer has completed assembly and test of the pack.
The ship mode is enabled by setting the SHIP bit in the MODE register and issuing the control command (data
0xA9 to register 0x00). Ship mode is entered only when the ship mode is enabled and the HDQ or CLK and/or
DTA line has been pulled low for at least 18 seconds. This allows the pack manufacturer to enable the ship
mode and pull the pack from the test equipment without any additional overhead. Transients on a
communication line after the ship mode has been enabled but before the device has entered ship mode, do not
cause the device to stay in active mode. Transients on a communication line, after the device has entered ship
mode can wake the part from ship mode, but if there is no charge or discharge activity above the DMF
threshold, the part automatically enters the Sleep mode as previously described.
All device functionality stops in ship mode and it does not start again until the communication lines are pulled
high or the battery voltage drops below and then rises above the V_(POR) threshold. A full reset is forced when the
part leaves ship mode. If the current NAC value must be retained after waking, ship mode should not be used.
Hibernate Mode
The device enters hibernate mode when V_CC drops below V_(POR). V_CC must be raised above V_(POR) in order to
exit the hibernate mode. If RBI voltage does not drop below 1.3 V, RAM content is maintained and allows
retention of NAC, LMD, CYCL, CYCT, and the CI flag after V_CC is raised above V_(POR).
Programming the EEPROM
The bqJUNIOR has 10 bytes of EEPROM that are used for firmware control and application data (see the
bqJUNIOR Register Descriptions section for more information). Programming the EEPROM should take place
during pack manufacturing because a 21 V pulse is needed on the PROG pin. The programming mode must be
enabled prior to writing any values to the EEPROM locations. The programming mode is enabled by writing to
the EE_EN register (address 0x6E) with data 0xDD. Once the programming mode is enabled, the desired data
can be written to the appropriate address. Figure 6 shows the method for programming all locations.
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