ACT2801/ACT2801B/ACT2801C
Rev 9, 14-Mar-17
Figure 11. Figure 12 gives out different fast charge
current with various RICST. The battery fast charge
current is estimated as the following equation:
Iin
Output
Cout
VIN
VOUT
SW
Input
Rcs
50mΩ
L
RICST (k )
RILIM
Ic(A) 1.25(A)
(4)
ILIM
Rcs(m )
Battery
Output
Cout
Input
VIN
RIN
VOUT
SW
Figure 7. Input current limit setting circuit
CIN
Ic
L
Input current limit at various resistor curve is shown
in Figure 8.
RICST
Rcs
50mΩ
Battery
ICST
CSP
CSN
3.0
VIN = 5.0V
Figure 11. Battery fast charge current setting
2.5
2.1
2.0
1.5
VIN = 5.0V
Vbat=3.7V
1.8
1.5
1.2
0.9
0.6
0.3
0
1.0
0.5
0
0.7 1.2 1.7 2.2 2.7 3.2 3.7 4.2 4.7
RILIM (kΩ)
Input current limit setting
The ILIMFigure 8.
is proportional to input current until input current is
limited, as shown in Figure 9.
pin voltage
0
10
20
30
40
50
60
70
80
RICST (kΩ)
Figure 12. Battery fast charge current setting
Boost
Output Constant Current
1.4
Boost output current is set by a resistor connected
from IOST pin to AGND as shown in Figure 13. The
boost output current is estimated as the following
equation:
VIN = 5.0V
RILIM=1.5kΩ
1.2
1.0
0.8
0.6
0.4
0.2
2
RIOST (k )
Rcs (m )
IIOST (A) (A)
(5)
3
Output
Cout
VOUT
Io
0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Rcs
50mΩ
Input current (A)
Figure 9. VILIM VS. input current
L
SW
RIOST
IOST
Battery
In
application,
CSP
CSN
if fast charge current setting is higher than input
current limit, must be parallel a 0.47uF capacitor
with RILIM as shown in Figure 10.
Figure 13. Boost output current setting circuit
Figure
14
Iin
gives out boost output current with various RIOST
.
Output
VIN
VOUT
Input
Cout
L
1.9
Rcs
50mΩ
VBAT = 3.7V
CVout=4.5V
CILIM
1.6
SW
Battery
1.3
1.0
0.7
0.4
ILIM
RILIM
Figure 10. Input current limit smaller than fast charge current
Battery Fast Charge Current
20
40
60
80
100
120
140
Battery fast charge current is set by a resistor
connected from ICST pin to AGND as shown in
RIOST (kΩ)
Boost output current setting
The IOSTFigure 14.
pin
Innovative PowerTM
- 14 -
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