AP1538

18V 3A 300KHz BUCK CONVERTER

AP1538

Rev.

2

2 of 14

JUNE 2008

www.diodes.com

Pin Assignments

(1) SOP-8L

(2) SOP-8L-DEP (Dual Exposed Pads)

1

2

3

4

8

7

6

5

FB

Output

OCSET

Output

EN

Vss

Vss

( Top View )

1

2

3

4

8

7

6

5

FB

Output

OCSET

Output

EN

Vss

Vss

1

2

( Top View )

(Note 3)

Notes:

3. Exposed pad 1 is connected to VSS and exposed pad 2 is connected to Output. The board layout for exposed pads needs to be considered to

avoid short circuit.

Pin Descriptions

Pin Name

Pin No.

Description

FB

1

Feedback pin

EN

2

Power-off pin

H: Normal operation

(Step-down operation)

L: Step-down operation stopped

(All circuits deactivated)

OCSET

3

Add an external resistor to set max output current

4

IC power supply pin

Output

5, 6

Switch Pin. Connect external inductor/diode here. Minimize trace

area at this pin to reduce EMI

7, 8

GND Pin