BQ27510_08 Datasheet, PDF (25/36 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge With Direct Battery Connection

bq27510
www.ti.com.......................................................................................................................................................... SLUS816A – MARCH 2008 – REVISED JUNE 2008
When PFC = 0 or 2, the bq27510 must be queried by the system in order to determine the battery temperature.
At that time, the bq27510 will sample the temperature. This saves battery energy when operating from battery, as
periodic temperature updates are avoided during charging mode.
POWER MODES
The bq27510 has four power modes: NORMAL, SLEEP, HIBERNATE and BAT INSERT CHECK. In NORMAL
mode, the bq27510 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. In HIBERNATE mode,
the fuel gauge is in a very low power state, but can be woken up by communication. Finally, the BAT INSERT
CHECK mode is a powered-up, but low-power halted, state, where the bq27510 resides when no battery is
inserted into the system.
The relationship between these modes is shown in Figure 2.
POR
Exit From HIBERNATE
Battery Removed
Exit From HIBERNATE
Communication Activity
AND Comm address is for bq27510
bq27500/1 clears Control Status
[HIBERNATE] = 0
Recommend Host also set Control
Status [HIBERNATE] = 0
BAT INSERT CHECK
Check for battery insertion
from HALT state.
No gauging
Flags [BAT_DET] = 0
Entry to NORMAL
Flags [BAT_DET] = 1
Exit From NORMAL
Flags [BAT_DET] = 0
HIBERNATE
Disable all bq27510
subcircuits except GPIO.
Negate /BAT_GD
Wakeup From HIBERNATE
Communication Activity
AND
Comm address is NOT for bq27510
NORMAL
Fuel gauging and data
updated every 1s
Entry to SLEEP
Operation Configuration[SLEEP] = 1
AND
| AverageCurrent( ) |≤ Sleep Current
Exit From SLEEP
Flags [BAT_DET] = 0
Exit From WAIT_HIBERNATE
Cell relaxed
AND
| AverageCurrent() | < Hibernate
OR
Cell relaxed
AND
VCELL < Hibernate Voltage
WAIT_HIBERNATE
Fuel gauging and data
updated every 20 seconds
/BAT_GD unchanged
Exit From WAIT_HIBERNATE
Host must set Control Status
[HIBERNATE] = 0
AND
VCELL > Hibernate Voltage
Exit From SLEEP
| AverageCurrent( ) | > Sleep Current
OR
Current is Detected above IWAKE
SLEEP
Fuel gauging and data
updated every 20 seconds
System Shutdown
Exit From SLEEP
(Host has set Control Status
[HIBERNATE] = 1
OR
VCELL < Hibernate Voltage
Figure 2. Power Mode Diagram
Copyright © 2008, Texas Instruments Incorporated
Product Folder Link(s): bq27510
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