AP1513

PWM CONTROL 2A STEP-DOWN CONVERTER

AP1513 Rev. 4

1 of 9

JULY 2009

DS31053

www.diodes.com

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Input voltage: 3.6V to 18V

•

•

Duty ratio: 0% to 100% PWM control

•

Oscillation frequency: 300KHz typ.

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Soft-start, Current limit, Enable function

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Thermal Shutdown function

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Built-in internal SW P-channel MOS

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SOP-8L: Available in “Green” Molding Compound

(No Br, Sb)

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Lead Free Finish/ RoHS Compliant (Note 1)

AP1513 consists of step-down switching regulator with PWM

control. These devices include a reference voltage source,

oscillation circuit, error amplifier, and internal PMOS.

AP1513 provides low-ripple power, high efficiency, and excellent

transient characteristics. The PWM control circuit is able to vary

the duty ratio linearly from 0 up to 100%. This converter also

contains an error amplifier circuit as well as a soft-start circuit that

prevents overshoot at startup.

An enable function, an over

current protect function and a short circuit protect function are built

inside, and when OCP or SCP happens, the operation frequency

will be reduced from 300KHz to 30KHz. Also, an internal

compensation block is built in to minimum external component

count.

With the addition of an internal P-channel Power MOS, a coil,

capacitors, and a diode connected externally, these ICs can

function as step-down switching regulators. They serve as ideal

power supply units for portable devices when coupled with the

SOP–8L mini-package, providing such outstanding features as

low current consumption. Since this converter can accommodate

an input voltage up to 18V, it is also suitable for the operation via

an AC adapter.

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PC Motherboard

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LCD Monitor

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Graphic Card

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DVD-Video Player

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Telecom Equipment

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ADSL Modem

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Printer and other Peripheral Equipment

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Microprocessor core supply

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Networking power supply

Typical Application Circuit

AP1513

+

-

V

SS

EN

C

C

R

A

R

B

D1

SBR2U30P1

FB

Vcc

Output

CVcc

V

V

IN

R

OCSET

OCSET

C

OUT

C

IN

Optional

C

OCSET

C

EN

R

EN

Option

100K

Note: V

R

L1

33uH

6.8K

1.3K

3K

0.1uF

+

-

C

0.1uF

470uF

470uF

0.1uF

2.5V

3.3V

5V

L1 Value

22uH

27uH

33uH

Features

General Description

Applications