ACT2823
REV 1, 01-DEC-2016
VLEDx(V)
VLEDx(V)
RLSx (kΩ)
turn on sequentially in a 0.5s interval prior to entering
the mode programmed by the PT pin.
RLSx (kΩ)
33.2
38.3
44.2
51.1
59
68.1
78.7
90.9
8.75
8.32
7.94
7.61
7.33
7.09
6.87
6.69
105
121
140
162
187
215
249
287
6.53
6.39
6.27
6.17
6.08
6.00
5.93
5.88
LED1-4 Fault Alarm Signal
When a fault is detected, all four LEDs turn on/off with
0.5s on and 0.5s off time for 10 seconds. The fault
conditions include battery OVP, UVP, OTP.
Bottom
Charging
Conventional
Circulating
Breathing
<25%
25%≤SOC<50%
50%≤SOC<75%
75%≤SOC<100%
EOC
Battery Impedance Compensation
TheACT2823 battery impedance function compensates
for the battery voltage changes due to changing battery
current. The battery current, charging or discharging,
interacts with the battery’s internal impedance to create
voltage increase or drop in battery voltage. The battery
impedance compensation circuitry counteracts this
changing voltage by adjusting the LED voltage
thresholds. This minimizes the number of LEDs that
change states as battery loading changes. Connecting
a resistor between the RIMC pin and AGND adjusts for
battery impedances between 100mΩ to 800mΩ. If
battery impedance compensation is not used, leave
RIMC open. The following equation calculates the
proper RIMC resistor value
Flash
Circulating on
Off
Always on
Breathing on/off
Figure 4: LED Indication Patterns
LED Threshold Setting
LED1, LED2, LED3 and LED4 thresholds are adjustable
with external resistors RLS1, RLS2, RLS3, and RLS4
connected from LEDLS1, LEDLS2, LEDLS3, LEDLS4
to AGND respectively, as shown in Figure 5. The LED
threshold voltage, Battery Impedance Compensation
voltage, and LED Hysteresis Window Setting voltage all
work together to program when the LEDs turn on and
off. Each of these three voltage are programmed
independently. Note that the battery voltage is
measured between the BATP and BATN pins.
RCS (m)
RBAT (m)
RIMC (k) 2160k
(4)
Where RCS is the current sense resistor in mΩ and RBAT
is the battery impedance in mΩ. For example, if
RCS=50mΩ and the battery impedance, RBAT, is 500mΩ,
then RIMC=216kΩ.
RHYST
RIMC
RLS1
RLS2 RLS3
RLS4
The following table calculates the proper RIMC resistor
for typical battery impedances and current sense
resistors.
RIMC(kΩ)
RBAT
(mΩ)
RCS=25mΩ RCS=50mΩ
ACT2823
100
200
300
400
500
600
700
800
540kΩ
270kΩ
180kΩ
135kΩ
108kΩ
90kΩ
1280kΩ
540kΩ
360kΩ
270kΩ
216kΩ
180kΩ
154kΩ
135kΩ
Figure 5: LED Threshold Setting
The following equation calculates the VLEDx threshold in
HZ mode. This threshold can be programmed between
5.5V to 8.8V.
77kΩ
67.5kΩ
108k
RLSx (k)
VLEDx(V ) 5.5V
(3)
The equation below calculates the ACT2823 LED
voltage threshold shift due to battery impedance
compensation.
Where RLSx is the resistance from LEDLSx to AGND in
kΩ. For example, setting RLS1 = 215kΩ results in
V
LED1=6V
Innovative PowerTM
ActiveSwitcherTM is a trademark of Active-Semi.
15
ACTIVE-SEMI [ ACTIVE-SEMI, INC ]
