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XC6804 Series
■ OPERATIONAL EXPLANATION (Continued)
● IC temperature monitoring function
In order to prevent destruction due to IC heat generation as well as abnormal charging due to thermal runaway, a thermal shutdown
circuit is incorporated into the IC. If the chip temperature rises to 115°C or higher and after 50ms elapses, this function turns off the output
driver and stops charging. When 50ms elapse with the chip temperature 105°C or less, this function returns the IC to the main charging
state and starts charging. Even when charging is stopped by this function, the t
TRK
and t
CHG
counts are continued.
● Dropout voltage monitoring function
To prevent reverse current from the Li-ion battery to the battery charger, this function monitors the dropout voltage between the BAT pin
voltage (V
BAT
) and power input pin voltage (V
IN
). When the V
IN
falls to VBAT + 40mV, the function turns off the output driver and switches the
backgating connection from the power pin to the BAT pin. When V
IN
rises higher than V
BAT
+ 0.1V, this function is released, the output driver
turns ON, the driver backgate connects to the power pin and resumes charging, and the charge status output pin turns ON. Even when
charging is stopped by this function, the t
CHG
count is continued. When charging is completed, the charging status output pin maintains the
OFF state even if the function activates due to disconnection of the input power or otherwise.
● UVLO function
A UVLO function is incorporated. If the power input pin voltage, V
IN
falls to 3.8V or lower during charging, this function turns off the output
driver and stops charging. In addition, the charge status output pin changes to OFF.
When the V
IN
rises to 4V or higher, the IC starts up and
charging begins. This function also detects voltage application to the power input pin.
● Charge over-voltage monitoring function
To prevent charging of a battery in the over-voltage state, this function stops charging if the BAT pin voltage rises to 4.45V or higher and
50ms elapses.
At this time, the charge status output pin repeats ON-OFF at 1kHz on the XC6804A, and turns off on the XC6804B. When voltage is
reapplied to the power input pin or the Li-ion battery is reconnected to the BAT pin, the IC starts up and charging begins.
● Charge over-current monitoring function
To prevent charging of a battery by excessive current, this function stops charging if the charge current rises to 1200 mA or higher.
At this time, the charge status output pin repeats ON-OFF at 1 kHz on the XC6804A, and turns off on the XC6804B. When voltage is
reapplied to the power input pin or the Li-ion battery is reconnected to the BAT pin, the IC starts up and charging begins.
● Recharge function
With the completion of charging, when the NTC thermistor temperature is 0°C or higher and less than 45°C, and the BAT pin voltage
(V
BAT
) falls to 3.9 V or less, charging resumes. (charging is resumed 150ms after the charge start state is entered.)
On the XC6804x4, if the NTC thermistor temperature is 45°C or higher and less than 60°C, charging automatically resumes when the
voltage falls to 3.75 V or less. This function is equiped only in the XC6804xxE, not in the XC6804xxD.
