MP2605 – 28V, 1A LINEAR BATTERY CHARGER WITH TRICKLE CHARGE AND TIMER

MP2605 Rev. 0.94

www.MonolithicPower.com

11

1/25/2010

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Charger Status Indication

The MP2605 has an integrated charge status pin

that remains low while the battery is charging.

reached, the CHG

pin will become high

impedance.

For different operation state, CHG indication is as

Table 2 shows.

Under full charge conditions, certain systems

may draw a very narrow current pulse that

may glitch. It is desirable to blank the CHG glitch

so that the system can properly indicate full

charge conditions to the user. A simple solution

is to add a RC filter on the

CHG pin to filter out

the possible CHG glitch, as shown in Figure 4.

Table 2—

CHG Indication for different Charge State

SHDN = High

Vin Fault

Battery Full

Time out Fault

Ambient

Temperature Fault

In Charging

CHG

HIGH

HIGH

Toggled at the

frequency

Hz

)

F

(

C

10

11

TMR

6

µ

×

−

HIGH

LOW

ACOK

TMR

4

NTC

9

IN

1

SS

7

SD

6

ACOK

3

CHG

2

GND

5

ISET

8

BAT

10

Figure 4—Filtered Charge Status with GPIO Connection