5.3.3 MACSubcmd() MAC Sleep
The sleep MAC command can override the requirement for bus low to enter SLEEP mode. In this case, the
part clock and data high condition is ignored for SLEEP to exit, though SLEEP will also exit if there is any
further communication. The BQ28Z610-R2 device can be sent to sleep with
MACSubcmd()
if specific sleep entry
conditions are met.
5.3.4 Wake Function
The BQ28Z610-R2 device can exit SLEEP mode if enabled by the presence of a voltage across SRP and
SRN. The voltage threshold needed for the device to wake from SLEEP mode is programmed in
Power:Wake
Comparator
.
Reserved (Bits 7–4, 1–0)
: Reserved. Do not use.
WK1,0 (Bits 3–2)
: Wake Comparator Threshold
WK1
WK0
Voltage
0
0
±0.625 mV
0
1
±1.25 mV
1
0
±2.5 mV
1
1
±5 mV
5.4 SHUTDOWN Mode
5.4.1 Voltage Based Shutdown
To minimize power consumption and avoid draining the battery, the device can be configured to shut down at a
programmable stack voltage threshold.
Status
Condition
Action
Enable
Min cell voltage <
Shutdown Voltage
OperationStatus()[SDV]
= 1
Trip
Min cell voltage continuous <
Shutdown Voltage
for
Shutdown
Time
Turn DSG FET off
Shutdown
Voltage at PACK terminal < Charger Present Threshold AND
Current()
≤ 0
Send device into SHUTDOWN mode
Exit
Voltage at PACK terminal > V
STARTUP
OR Min cell voltage >
Shutdown Voltage
if not in SHUTDOWN mode
OperationStatus()[SDV]
= 0
Return to NORMAL mode
Note
The device goes through a full reset when exiting from SHUTDOWN mode, which means the device
will reinitialize. On power up, the gauge checks certain special memory locations. If the memory
checksum is incorrect, or if either the gauge of the AFE watchdog has been triggered, the gauge will
do a full reset.
If the memory checksum is good, for example in the case of a short power glitch, the gauge will do a
partial reset. The initialization is faster in partial reset, and certain memory data will not be reinitialized
(for example, all SBS registers, last known FET state, last ADC and CC readings, and so on) and so a
partial reset is usually transparent to the host.
5.4.2 MACSubcmd() MAC Shutdown
In SHUTDOWN mode, the device turns off the CHG and DSG FETs after
FET Off Time
, and then shuts down
to minimize power consumption after
Delay
time. Both
FET Off Time
and
Delay
time are referenced to the time
the gauge received the command. Thus, the
Delay
time must be set longer than the
FET Off Time
. The device
returns to NORMAL mode when the voltage at PACK terminal > V
Startup–
. The device can be sent to this mode
with the
MACSubcmd()Shutdown
command. Charger voltage must not be present for the device to enter SHIP
Power Modes
32
BQ28Z610-R2
Copyright © 2022 Texas Instruments Incorporated
