ACE4704
Fully 5A, 4cell Standalone Li-ion Battery Charger
Oscillator
Switching Frequency
Maximum Duty Cycle
fosc
240
300
94
360
kHZ
%
Dmax
Sleep Mode
VCC falling
VBAT=8V
VBAT=12V
VBAT=18V
VBAT=8V
0.06
0.1
0.1
0.14
0.18
0.28
0.39
0.52
0.58
Sleep Mode Threshold
VSLP
0.14
0.23
0.32
0.42
0.47
V
V
(measure VCC-VBAT
)
0.18
0.26
0.32
0.38
Sleep mode Release
Threshold (measure
VSLPR
VCC rising
VBAT=12V
VBAT=18V
VCC-VBAT
)
DRV Pin
VDRV High (VCC-VDRV
)
VH
VL
IDRV=-10mA
60
mV
V
VDRV Low (VCC-VDRV
)
IDRV=0mA
Cload=2nF, 10% to
90%
5
6.5
8
Rise Time
tr
tf
30
40
40
65
ns
ns
Cload=2nF, 90% to
10%
Fall Time
30
65
Detailed Description
The ACE4704 is a constant current, constant voltage Li-Ion battery charger controller that adopts PWM
step-down (buck) switching architecture. The charge current is set by an external sense resistor (RCS)
across the CSP and BAT pins. The final battery regulation voltage in constant voltage mode is internally
set to 16.8V for ACE4704 with 1% accuracy.
A charge cycle begins when the voltage at the VCC pin rises above the UVLO level and is greater than
the battery voltage by VSLPR. At the beginning of the charge cycle, if the battery voltage is less than 11.2V,
the charger goes into trickle charge mode. The trickle charge current is internally set to 15%(Typical) of
the full-scale current. When the battery voltage exceeds 11.2V, the charger goes into the full-scale
constant current charge mode. In constant current mode, the charge current is set by the external sense
resistor RCS and an internal 200mV reference, so the charge current equals to 200mV/RCS. When the
battery voltage approaches the regulation voltage, the charger goes into constant voltage mode, and the
charge current will start to decrease. When the charge current drops to a level that is set by the resistor at
EOC pin, the charge cycle is terminated, the DRV pin is pulled up to VCC, and an internal comparator
turns off the internal pull-down N-channel MOSFET at the CHRG pin to indicate that the charge cycle is
terminated. During the charge cycle termination status, another internal pull-down N-channel MOSFET at
the DONE pin is turned on to indicate the termination status.
To restart the charge cycle, just remove and reapply the input voltage. Also, a new charge cycle will
begin if the battery voltage drops below the recharge threshold voltage of 16V.
When the input voltage is not present, the charger goes into sleep mode.
A 10kΩ NTC (negative temperature coefficient) thermistor can be connected from the TEMP pin to
ground for battery temperature qualification. The charge cycle is suspended if the battery’s temperature is
outside of the acceptable range.
VER 1.2
5
ACE [ ACE TECHNOLOGY CO., LTD. ]
