MP2625B – SINGLE CELL SWITCHING CHARGER WITH POWER PATH CONTROL

MP2625B Rev. 1.01

www.MonolithicPower.com

24

1/15/2018

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APPLICATION INFORMATION

COMPONENT SELECTION

Setting the Input Current Limit

First the input current limit can be set by the M0

and M1 pins refer to the Table 1, the exact

current value in minimum, typical and maximum

is listed in the EC table.

Under program mode, connect a resistor from

the ILIM pin to AGND to program the input

current limit for different input ports. The

relationship between the input current limit and

setting resistor is as Equation (1) which is

shown in following again:

IN_LIM

ILIM

40000

I

=1.14

(mA)

R(kΩ)



(1)

The tolerance is ±8% of the input current limit

setting.

So for a required minimum input current limit

value, just calculate its typical value first, then

calculate the setting resistor based on Equation

(1). Also the maximum value can be calculated

according to the tolerance.

1% accuracy

resistor is used for this setting. Also, for a given

calculated. Following table is an example:

Therefore, if customer selected a 54.9k in 1%

accuracy resistor for the input current limit

setting, then the typical input current limit value

is 830.6mA, the minimum is 756.6mA and the

maximum is 906mA.

Setting the Charge Current

between the charge current and setting resistor

is as Equation (2) which is shown in following

again:

CHG

SET

1800

I1.15

(mA)

R(k )





(2)

minimum or maximum charge current is

required, first the typical value should be

calculated according to the tolerance. After that,

calculate the resistor according to formula (2).

1% accuracy resistor is used for this setting.  

For a given setting resistor, the charge current

can be calculated by the same way did in the

input current limit setting. Usually in USB mode,

the charge current is always set over the USB

input limit specification. Then the MP2625

regulates the input current constant at the

limitation value. Thus the real CC charge

current is not the setting value, it varies with

different input and battery voltages.

The maximum CC charge value can be

calculated as:

)

A

(

V

I

V

I

TC

ILIM

IN

MAX

_

CC









(3)

is the current charge efficiency. Assume

Figure 7 shows a calculating charge current

curve by limiting the input current limit.

Current Limit

Setting the Input Voltage Limit

The input clamp voltage is set using a resistive

voltage divider from the input voltage to VLIM

pin. The voltage divider divides the input

voltage down to the limit voltage by the ratio:

Resistor 

(kΩ) 

(mA) 

8% ‐8%

Typ. 

54.9  830.601  897.049  764.153

Min. 

54.351  838.991 

906.11  771.872

Max. 

55.449  822.377  888.168  756.587