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XC8108

Series

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OPERATIONAL EXPLANATION (Continued)

<Current limit external adjustment function> (Continued)

Fig1. Current limit set value

XC8108 電流制限設定値 － 外部抵抗値

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

2100

2200

2300

2400

2500

0

5

10

15

20

25

30

35

40

<Reverse current prevention>

If the reverse-voltage state lasts for 4ms (TYP.), the FLG pin changes to Low level output.

Two types are available for the reverse current prevention circuit: the auto recovery type (product type C) and the latch off

type (product type D). After the reverse current prevention circuit activates and the FLG pin outputs low level, the operation is

different between these two types.

On the auto recovery type, when the output voltage drops below the input voltage, the reverse current prevention circuit stops

immediately, and the power switch transistor turns on again. If the output voltage remains lower than the input voltage for 4ms

(TYP.), the FLG pin returns to High level output.

On the latch off type, the power switch transistor remains in the off state even if the reverse voltage state is released.

Latch operation is released by turning off the IC with the CE pin signal and then restarting, or by lowering the input voltage

below the UVLO detected voltage once and after that raising it higher than UVLO released voltage.

XC8108 Current limit set value vs. External resistor