LTC4099 Linear Technology Corporation, LTC4099 Datasheet - Page 19

• Manufacturer Part Number: LTC4099
• Description: I2C Controlled USB Power Manager/Charger
• Manufacturer: Linear Technology Corporation

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OPERATION
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
section.
2
C port. See the Overtemperature Battery Conditioner
NO
INDICATE BATTERY FAULT
TIMER > 30 MINUTES
RUN EVENT TIMER
INHIBIT CHARGING
CHARGE WITH
103V/R
BAT > 2.85V
PROG
YES
YES
BAT < 2.85V
NO
INDICATE CHARGING
CONSTANT-CURRENT
CLEAR EVENT TIMER
PAUSE EVENT TIMER
NTC OUT-OF-RANGE
THROUGH V
THROUGH V
POWER AVAILABLE
BATTERY STATE
CHARGE WITH
BAT FALLING
BAT RISING
Figure 4. Battery Charger Flow Chart
NO
2.85V < BAT < V
NO
NO
RECHRG
RECHRG
YES
BAT > V
YES
YES
FLOAT
FLOAT
–
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
is updated at the end of each sample period.
–
INDICATE CHARGING
RUN EVENT TIMER
STOP CHARGING
FIXED VOLTAGE
CHARGE WITH
BAT < V
SAFETY TIMER
EXPIRED
STOPPED
RECHRG
YES
YES
NO
NO
INDICATE C/x REACHED
PAUSE EVENT TIMER
INDICATE NTC FAULT
INHIBIT CHARGING
I
BAT
< C/x
YES
LTC4099
NO
4099 F04
19
2
C port
4099f