ACT2813/ACT2813C
Rev 2, 19-May-15
table 3. The LED status is based on battery voltage
and operation modes. When battery voltage is low,
LED1 is flashing. In charge mode, when a battery is
fully charged, flashing stops and all the 4 LEDs are
solid on.
APPLICATIONS INFORMATION
Battery level voltage shift (BLVS pin)
LED1-4 voltage thresholds are adjusted from HZ
mode during charging and discharging based on
the compensated impedance. Those thresholds are
programmed by a resistor connected from BLVS
pin to AGND as shown in Figure 5. The following
equation shows the LED4 voltage threshold:
Fast Charge Current
Battery fast charge current is set by a resistor
connected from ICST pin to AGND as shown in
Figure 6.
The battery fast charge current is estimated as the
following equation:
VBATLED4(V ) = 3.5(V )+0.01(mA)×RBLVS(kΩ )
(1)
RICST (kΩ )
Rcs(mΩ )
Ic(A) =1.25(A)×
(2)
Figure 5. Battery level voltage shift setting circuit
As long as LED4 is set, all the other 3 LED
thresholds is fixed as shown in the table 2:
Figure 6. Battery fast charge current setting circuit
Table 2: 4 LED Voltage Thresholds
Figure 7 gives out different fast charge current with
various RICST
.
RBLVS (ohm)
LED1
50K
60K
70K
80K
3.0
2.5
2.0
1.5
1.0
0.5
3.55V
3.65V
3.80V
4.00V
3.65V
3.75V
3.90V
4.10V
3.75V
3.85V
4.00V
4.20V
3.85V
3.95V
4.10V
4.30V
VIN = 5.0V
Vbat=3.7V
LED2
LED3
LED4
0
0
LED Status Indication
10
20
30
40
50
60
RICST (kΩ)
4 LEDs ON/OFF and flash show the charge status
and the remained capacity level as shown in the
Figure 7. Battery fast charge current setting
Table 3: LED Indication
Charge Mode
PB time>30ms (Boost or HZ Mode)
LED
LED1
Flash
LED2
Off
LED3
LED4
Off
LED1
Off
LED2
Off
LED3
Off
LED4
Off
VBAT<2.9V
Off
2.9V≤VBAT<LED1
LED1≤VBAT<LED2
LED2≤VBAT<LED3
LED3≤VBAT<LED4
VBAT≥LED4
Flash
On
Off
Flash
On
Off
Off
Off
Off
Flash
On
Off
Off
On
On
On
On
Off
Off
Off
On
On
On
Off
Off
Off
Off
On
On
On
Flash
On
Off
On
On
On
Flash
Flash
On
On
On
On
On
On
VBAT≥LED4 (End of Charge)
On
On
On
On
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