Datasheet

LTC4099
19
4099fd
occurs, it may be desirable to have application software
enforce an emergency reduction of power in the portable
product. It is possible to enable the battery conditioner
circuit at this temperature to reduce stress caused by
simultaneous high temperature and high voltage via the
I
2
C port. See the Overtemperature Battery Conditioner
section.
The thermistor
detection circuit samples the thermistor’s
value continuously
whenever charging is enabled and
periodically when it is not. When the charger is not en-
abled, the thermistor is sampled for 150µs approximately
every 150ms. The thermistor data available to the I
2
C port
is updated at the end of each sample period.
CLEAR EVENT TIMER
NTC OUT-OF-RANGE
INDICATE NTC FAULT
CHARGE WITH
CONSTANT-CURRENT
PAUSE EVENT TIMER
INHIBIT CHARGING
PAUSE EVENT TIMER
CHARGE WITH
FIXED VOLTAGE
RUN EVENT TIMER
CHARGE WITH
103V/R
PROG
RUN EVENT TIMER
INDICATE CHARGING
POWER AVAILABLE
TIMER > 30 MINUTES
SAFETY TIMER
EXPIRED
BAT > 2.85V BAT < V
RECHRG
I
BAT
< C/x
NO
NO
YES
YES
YES
YES
YES
YES
NO
NO
BAT > V
FLOAT
– EBAT < 2.85V
2.85V < BAT < V
FLOAT
– E
NO
NONO
INHIBIT CHARGING STOP CHARGING
INDICATE BATTERY FAULT
BAT RISING
THROUGH V
RECHRG
BAT FALLING
THROUGH V
RECHRG
INDICATE CHARGING
STOPPED
INDICATE C/x REACHED
4099 F04
NO
YES
YES
BATTERY STATE
Figure 4. Battery Charger Flow Chart
operaTion