AIC1782
Functioning of -∆V detection and peak voltage
timer ( 0
∆
V ) can be disabled if the MODE pin is
biased to GND. Functioning of
∆
T /
∆
t detection
can be disabled if the voltage of ADJ pin is
higher than V
CC
- 0.3V.
Maximum Safety Timer Cutoff
The maximum fast charge period is determined
by the safety timer, which is set by a resistor
connected from TMR pin to GND. Safety timer,
-∆V sampling rate, and
∆
T /
∆
t sampling rate
will be longer if the resistor value is larger.
When the value of the resistor is 100KΩ, the
safety timer period equals 80 minutes. This can
be verified by biasing MODE pin to V
CC
and the
measured frequency on DSW pin should be
around 32.8 KHz. After the safety timer period is
finished, the fast charge action is terminated.
Maximum Voltage and Temperature Cutoff
The AIC1782 guards against the maximum
limits for battery voltage and temperature during
fast charging. If either of these limits is ex-
ceeded, fast charge action is terminated.
Trickle Charge
There are five different selectable duty cycles
for trickle charge after the fast charge to prevent
the loss of charge due to battery self-
discharging. The setting of SEL1 and SEL2 pins
controls the duty cycle
.
This function can only
be activated on the following three situation:
Battery pack A is charge full and battery
pack B is abnormal.
Battery pack B is charge full and battery
pack A is abnormal.
Battery pack A and B are both charge full.
(c)
(b)
V
CC
- 1.4V> SEL3 >
The acceptable battery voltage range of ABV
and BBV pins and mode of temperature protec-
tion function is determined by the voltage of
SEL3 pin, shown as the following:
(a)
SEL3 > V
CC
- 0.3V
Acceptable ABV/BBV Range:
Before initial timer: 0.16V~2.7V
After initial timer: 0.69V~2.7V
Temperature Protection Mode:
Entering charge-suspending mode when tem-
perature is either too low or too high, same as
abnormal battery voltage. Latch for charge-
suspending function is provided for high tem-
perature protection, but not for low temperature
protection.
V
cc
- 0.4V
2
Acceptable ABV/BBV Range:
Before initial timer: 0.16V~2.7V
After initial timer: 0.69V~2.7V
Temperature Protection Mode:
If temperature is too high, battery charging
is regarded as completed. If temperature is
too low, function of
∆
T /
∆
t detection is
disabled, just as thermistor is not existing.
V
cc
- 0.4V>SEL3 >1.4V
2
Acceptable ABV/BBV Range:
Before initial timer: 0.16V~2 V
After initial timer:1.2V~2V
Temperature Protection Mode:
Entering charge-suspending mode when
temperature is either too low or too high,
same as abnormal battery voltage. Latch
for charge-suspending function is provided
for high temperature protection, but not for
low temperature protection.
DESIGN GUIDE
ABV/BBV Range and Temperature Protec-
tion
15
AIC [ ANALOG INTERGRATIONS CORPORATION ]
