BQ2063_15 Datasheet, PDF (12/60 Pages) Texas Instruments – SBS v1.1-COMPLIANT Li-ION GAS-GAUGE IC

bq2063
Not Recommended For New Designs
SBS v1.1ĆCOMPLIANT LiĆION GASĆGAUGE IC
WITH PROTECTOR INTERFACE
SLUS468E− MAY 2001 − REVISED APRIL 2002
self-discharge (continued)
The timer that keeps track of the self-discharge update time is halted whenever charge activity is detected. The
timer is reset to zero if the bq2063 reaches the RemainingCapacity( )=FullChargeCapacity( ) condition while
charging.
1200
CAPACITY
vs
TIME
1000
800
TA = 15°C
600
TA = 25°C
400
200
0
0
TA = 35°C
TA = 45°C
10
20
30
40
50
60
70
Time − Days
Figure 6. Self-Discharge at 2.5%/Day at 25°C
This means that a 0.39% reduction of RM is made 12.8 times per day to achieve the desired 5% per day
reduction at 35°C.
Figure 6 illustrates how the self-discharge estimate algorithm adjusts RemainingCapacity( ) vs temperature.
light discharge or suspend current compensation
The bq2063 can be configured in two ways to compensate for small discharge currents that produce a signal
below the digital filter. First, the bq2063 can decrement RM and DCR at a rate determined by the value stored
in Light Discharge Current EE 0x64 when it detects no discharge activity and the SMBC and SMBD lines are
high. Light Discharge Current has a range of 0 mA to 11.2 mA, with 44 µA granularity.
Alternatively, the bq2063 can be configured to disable the digital filter for discharge when the SMBC and SMBD
lines are high. In this way, the digital filter does not mask the leakage-current signal. The bq2063 is configured
in this mode by setting the NDF bit in Control Mode.
battery electronic load compensation
The bq2063 can be configured to compensate for a constant load present in the battery pack at all times, such
as from battery electronics. The bq2063 applies the compensation continuously when the charge or discharge
is below the digital filter. The bq2063 applies the compensation in addition to self-discharge. The compensation
occurs at a rate determined by the value stored in Pack Load Estimate EE 0x1c. The compensation range is
0 µA–700 µA in steps of approximately 2.75 µA.
12
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265