SHUTDOWN mode. If there is charger voltage present or charge current is flowing, the device will wait until the
charger is removed to enter the SHUTDOWN state. This is to prevent the device from unintended, immediate
wake-up. The
Shutdown()
command cannot be canceled.
Note
If the gauge is unsealed and the MAC
Shutdown()
command is sent twice in a row, the gauge will
execute the shutdown sequence immediately and skip the normal delay sequence.
5.4.3 Time Based Shutdown
The device can be configured to shut down after staying in SLEEP mode without communication for a preset
time interval specified in the
Auto Ship Time
. Setting the
PowerConfig[AUTO_SHIP_EN]
= 1 enables this
feature. Any communication to the device will restart the timer. When the timer reaches the Auto Ship Time,
the time-based shutdown effectively triggers the MAC shutdown command to start the shutdown sequence. The
device returns to NORMAL mode when voltage at PACK terminal > V
Startup–
.
5.4.4 Emergency FET Shutdown
The Emergency FET Shutdown function provides an option to disable the battery power to the system by
opening up the CHG and DSG FETs before removing an embedded battery pack. The EMERGENCY FET
SHUTDOWN state is enabled by setting
DA Configuration[EMSHUTEN]
= 1. It is entered by sending a Manual
FET Control (MFC) sequence to
ManufacturerAccess()
.
When the gauge is in the EMERGENCY FET SHUTDOWN state, the
OperationStatus()[EMSHUT]
= 1.
The manual FET control (MFC) sequence to put the gauge into the EMERGENCY FET SHUTDOWN state is
described below.
1. Send word 0x270C to
ManufacturerAccess()
(0x00) to enable the MFC.
2. Within 4 s, send word 0x043D to
ManufacturerAccess()
(0x00) to turn off CHG and DSG FETs.
3. The CHG and DSG FETs will be turned off.
5.4.4.1 Exiting Emergency FET Shutdown
The gauge can exit the EMSHUT mode by turning on the CHG and DSG FETs with any one of the following
conditions:
• Send word 0x23A7 to
ManufacturerAccess()
(0x00).
• Voltage at Pack pin >
Charger Present Threshold
for two sample periods (that is, ~500 ms)
• Valid I
2
C bus communication is received. Valid I
2
C bus communication means a valid gauge address and any
command is received (that is, an invalid command with a valid address is OK).
In EMSHUT mode, to detect the voltage level at the Pack pin quickly (even while in SLEEP), the AD conversion
occurs every second.
Power Modes
SLUUCO0 – APRIL 2022
BQ28Z610-R2
33
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