MP2606 – SINGLE CELL 1A LINEAR LI-ION BATTERY CHARGER W/O TRICKLE CHARGE
MP2606 Rev. 1.0 www.MonolithicPower.com 7
1/25/2010 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2010 MPS. All Rights Reserved.
2.6V 4.2V
V
BATT
10% of I
CHG
I
BFL
CC
Charging
Charging
Complete
CV
Charging
I
CHG
I
BATT
Figure 2—MP2606 Typical Charging Profile
Charge
Start
Charge
End
Soft-Start
Time
CC
Mode
CV
Mode
10% of I
CHG
(I
BFL
)
90% of I
CHG
I
CHG
4.2V
V
BATT
V
BATT
I
BATT
I
BATT
CHG
Figure 3—MP2606 Typical Charging
Procedure
Battery Over-Voltage Protection and
Automatic Recharge
At any time when V
BATT
is 50mV higher than the
trimmed charge target, the MP2606 reduces its
charge current to 0µA. This ensures the safety
of the battery. Also, the CV control loop always
monitors the battery voltage such that it will
automatically recharge the battery when it is
depleted below the target level.
Programming of Charge Current and Battery
Full Current
The charge current (I
CHG
) is set by a resistor
(R
CHG
) connecting from the ISET pin to GND.
The relationship of the charge current and the
programming resistance is established by the
following table and graph.
Table 1—R
CHG
and I
CHG
Relationship
R
CHG
(kΩ) I
CHG
(mA)
1.82 913
2 835
2.16 778
2.5 677
3.32 521
4.32 410
5 357
7.5 236
8.45 208
10 176
Charge Current vs
1/R
CHG
Resistance
1000
900
800
700
600
500
400
300
200
I
CHG
CURRENT
(mA)
0.00 0.20
0.10
0.30 0.40
0.600.50
1/R
CHG
100
0
Figure 4—Charge Current vs 1/R
CHG
Resistance
The recommended resistance for programming
the charge current is 2.3kΩ<R
CHG
<11kΩ. The
battery full charge current threshold (I
BFL
) is
programmed by connecting a resistor R
BFL
from
the IBFL pin to GND:
(1)
BFL
BFL
R
1.7kΩ1
I
×
=
(2)
BFLBFH
BFH
//RR
1.7kΩ1A
I
×
=
Where 2R
CHG
<R
BFL
<10R
CHG
. The open-drain pin
CHG
is used to indicate charging status. When
the battery full condition is reached or any other
condition prevents the charger from charging,
CHG will become a floating pin.
