MP2603 – SINGLE CELL 150mA LINEAR LI-ION BATTERY CHARGER

MP2603 Rev. 1.01

www.MonolithicPower.com

7

1/31/2013

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© 2013 MPS. All Rights Reserved.

OPERATION

The MP2603 is enabled with a minimum input

supply voltage of 3.5V. This power supply must

also be higher than both the UVLO threshold

and the battery voltage. There is an internal

500kΩ pull-down resistor connecting the IN and

GND pins. The MP2603 provides CC/CV

charge algorithms to automatically change

modes depending on the battery status. Figure

2 shows the typical charging procedure for the

MP2603.

Trickle

Charging

Charge

Start

Charge

End

Soft-Start

Time

Thermal

Regulation

CC

Mode

CV

Mode

2.6V

4.2V

Figure 2—MP2603 Typical Charging

Procedure

ground. The relationship of the charge current

and the programming resistance is established

by the following equation and graph. The

Table1 lists the typical application setting of

Ichg.

PGM

CHG

R

k

53

.

2

mA

150

I

Ω

×

=

(1)

12.4

30

7.2

52

4.99

76

3.74

101

2.5

151

180

150

120

90

60

30

0

0.0

0.1

0.2

0.3

0.4

0.5

Charge Current vs

Resistance

When battery voltage falls below the trickle

threshold (2.6V), charge current is limited to

10% of the programmed value to trickle charge

the fully depleted battery. After the battery

voltage reaches 2.6V, the charger begins to

charge

at

the

constant

current

of

the

Constant Current (CC) mode. Once the battery

voltage reaches 4.2V, the charger will operate

in the Constant Voltage (CV) mode until the

battery is fully charged.

Charge Status (CHGZ)

The open-drain CHGZ pin monitors charge

and/or a resistor. The end-of-charge, or battery

full, is indicated by the CHGZ pin changing from

decreases to 10% of the programmed value.

Thermal Protection

To

prevent

overheating,

the

MP2603

automatically limits the die temperature to

130°C by reducing the internal current-setting

reference voltage. In the thermal protection

mode, the charge current reduces automatically,

but remains continuous.