BQ27620-G1 Datasheet, PDF (32/45 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge

bq27620-G1
SLUSAE3 – OCTOBER 2012
POR
www.ti.com
Exit From HIBERNATE
Battery Removed
Exit From HIBERNATE
Communication Activity
AND Comm address is for bq27520
bq27520 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
HIBERNATE
Disable all bq27620
subcircuits except GPIO.
Negate BAT_GD
Wakeup From HIBERNATE
Communication Activity
AND
Comm address is NOT for bq27620
Entry to NORMAL
Flags [BAT _DET] = 1
NORMAL
Exit From NORMAL
Flags [BAT _DET] = 0
Fuel gauging and data
updated every 1s
Entry to SLEEP
Operation Configuration[SLEEP] = 1
AND
| EffectiveCurrent | ≤ Sleep Current
AND
Control Status[SNOOZE] = 0
Exit From SLEEP
Flags [BAT_DET] = 0
Exit From SLEEP
| EffectiveCurrent( ) | > Sleep Current
OR
Current is Detected above IWAKE
Exit From WAIT_HIBERNATE
Cell relaxed
AND
| EffectiveCurrent | < Hibernate
Current
OR
Cell relaxed
AND
VCELL < Hibernate Voltage
WAIT_HIBERNATE
Fuel gauging and data
updated every 20 seconds
BAT_GD unchanged
System Shutdown
Exit From WAIT _HIBERNATE
Host must set Control Status
[HIBERNATE ] = 0
AND
VCELL > Hibernate Voltage
SLEEP
Fuel gauging and data
updated every 20 seconds
(LFO ON and HFO OFF)
Exit From SLEEP
(Host has set Control Status
[HIBERNATE] = 1
OR
V_CELL < Hibernate Voltage
System Sleep
Figure 5-1. Power Mode Diagram
5.3.5 Battery Detection Using the BI/TOUT Pin
During power-up or hibernate activities, or any other activity where the bq27620-G1 needs to determine
whether a battery is connected or not, the fuel gauge applies a test for battery presence. First, the
BI/TOUT pin is put into high-Z status. The weak 1.8MΩ pull-up resistor will keep the pin high while no
battery is present. When a battery is inserted (or is already inserted) into the system device, the BI/TOUT
pin will be pulled low. This state is detected by the fuel gauge, which polls this pin every second when the
gauge has power. A battery-disconnected status is assumed when the bq27620-G1 reads a thermistor
voltage that is near 2.5V.
5.3.6 SOC_INT pin
The SOC_INT pin generates a pulse of different pulse widths under various conditions as indicated by the
table below. After initialization only one SOC_INT pulse will be generated within any given one second
time slot and therefore, may indicate multiple event conditions.
32
FUNCTIONAL DESCRIPTION
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