BQ27541-V200_17 Datasheet, PDF (29/46 Pages) Texas Instruments – Single Cell Li-Ion Battery Fuel Gauge for Battery Pack Integration

Not Recommended for New Designs
bq27541-V200
www.ti.com
SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013
The charging should not start when the temperature is below the Charge Inhibit Temp Low or above the
Charge Inhibit Temp High. The charging can continue if the charging starts inside the window [Charge Inhibit
Temp Low, Charge Inhibit Temp High] until the temperature is either below Suspend Temperature Low or
above the Suspend Temperature High. Therefore, the window [Charge Inhibit Temp Low, Charge Inhibit
Temp High] must be inside the window of [Suspend Temperature Low, Suspend Temperature High].
POWER MODES
The bq27541 has three power modes: NORMAL, SLEEP, and HIBERNATE. In NORMAL mode, the bq27541 is
fully powered and can execute any allowable task. In SLEEP mode the fuel gauge exists in a reduced-power
state, periodically taking measurements and performing calculations. Finally, in HIBERNATE mode, the fuel
gauge is in a very low power state, but can be awaken by communication or certain I/O activity.
The relationship between these modes is shown in Figure 3. Details are described in the sections that follow.
POR
Exit From HIBERNATE
VCELL < POR threshold
Exit From HIBERNATE
Communication Activity
OR
bq27541 clears Control Status
[HIBERNATE] = 0
Recommend Host also set Control
Status [HIBERNATE] = 0
NORMAL
Fuel gauging and data
updated every 1s
Exit From SLEEP
Pack Configuration [SLEEP] = 0
OR
| AverageCurrent( ) | > Sleep Current
OR
Current is Detected above IWAKE
HIBERNATE
Disable all bq27541
subcircuits except GPIO.
Wakeup From HIBERNATE
Communication Activity
AND
Comm address is NOT for bq27541
Entry to SLEEP
Pack Configuration [SLEEP] = 1
AND
| AverageCurrent( ) |≤ Sleep Current
SLEEP
Fuel gauging and data
updated every 20 seconds
Exit From WAIT_HIBERNATE
Host must set Control Status
[HIBERNATE] = 0
AND
VCELL > Hibernate Voltage
Entry to WAITFULLSLEEP
Host must set Control Status
[FULLSLEEP]=1 and
Full Sleep Wait Time > 0
Exit From WAITFULLSLEEP
Any Communication Cmd
WAITFULLSLEEP
FULLSLEEP Count Down
Exit From WAIT_HIBERNATE
Cell relaxed
AND
| AverageCurrent() | < Hibernate
Current
OR
Cell relaxed
AND
VCELL < Hibernate Voltage
WAIT_HIBERNATE
Fuel gauging and data
updated every 20 seconds
System Shutdown
Exit From SLEEP
(Host has set Control Status
[HIBERNATE] = 1
OR
VCELL < Hibernate Voltage
Entry to FULLSLEEP
Host must set Control Status
[FULLSLEEP] = 1 and
Full Sleep Wait time ≤ 0
Entry to FULLSLEEP
Count <1
FULLSLEEP
Exit From
FULLSLEEP
Any
Communication
Cmd
In low power state of SLEEP
mode. Gas gauging and data
updated every 20 seconds
System Sleep
Figure 3. Power Mode Diagram
NORMAL MODE
The fuel gauge is in NORMAL Mode when not in any other power mode. During this mode, AverageCurrent( ),
Voltage( ) and Temperature( ) measurements are taken, and the interface data set is updated. Decisions to
change states are also made. This mode is exited by activating a different power mode.
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Product Folder Links: bq27541-V200
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