Datasheet

CHARGESUSPENDED CHARGESUSPENDED
TEMPERATURERANGE TO
INITIATECHARGE
TEMPERATURERANGE
DURING A CHARGECYCLE
V
HTF
GND
V
TCO
GND
VREF
VREF
CHARGESUSPENDED CHARGESUSPENDED
V
LTF
V
LTF
CHARGEatI /8
CHARGE
CHARGEat I /8
CHARGE
V
WARM
CHARGEat I /8
CHARGE
CHARGEat I /8
CHARGE
V
COOL
CHARGEat I
CHARGE
CHARGEat I
CHARGE
V
COOL
V
WARM
V
LTF_HYS
V
COOL_HYS
V
WARM_HYS
Temperature
Programmed
ChargeCurrent
1/8xProgrammed
ChargeCurrent
Charge
Current
Charge
Suspended
I
CHARGEG
/8
Charge
Chargeat I
CHG
I /8
CHARGE
Charge
Charge
Suspended
V
LTF
V
COOL
V
WARM
V
HTF
/V
TCO
(I )
CHARGE
(I /8)
CHARGE
bq24620
SLUS893A –MARCH 2010– REVISED OCTOBER 2011 www.ti.com
charge and the safety timer and waits until the battery temperature is within the V
LTF
to V
HTF
range. If the battery
temperature is between the V
LTF
and V
COOL
thresholds or between the V
HTF
and V
WARM
thresholds, charge is
automatically reduced to I
CHARGE
/8. To avoid early termination during COOL/WARM condition, set I
TERM
≤
I
CHARGE
/10. The controller suspends charge by turning off the PWM charge FETs. Figure 12 and Figure 13
summarize the operation.
Figure 12. TS, Thermistor Sense Thresholds
Figure 13. Typical Charge Current vs Temperature Profile
Assuming a 103AT NTC thermistor on the battery pack as shown in the Typical System Schematic (Figure 1),
the values of RT1 and RT2 can be determined by using Equation 5 and Equation 6:
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