AP3418

Document number: DS37233 Rev. 3 - 2

1 of 11

www.diodes.com

November 2014

© Diodes Incorporated

AP3418

A Product Line of

Diodes Incorporated

1.5A, 1.4MHZ HIGH EFFICIENCY SYNCHRONOUS DC-DC BUCK CONVERTER

Description

The AP3418 is a 1.4MHz fixed frequency, current mode, PWM

synchronous buck (step-down) DC-DC converter, capable of driving a

1.5A load with high efficiency, excellent line and load regulation. The

device integrates synchronous P-channel and N-channel power

MOSFET switches with low on-resistance. It is ideal for powering

portable equipment that runs from a single Li-ion battery.

A standard series of inductors are available from several different

manufacturers optimized for use with the AP3418. This feature greatly

simplifies the design of switch-mode power supplies.

The AP3418 is available in SOT25 package.

Features



Input Voltage Range: 2.5V to 5.5V





ADJ Output



Fixed 1.4MHz Frequency



High Efficiency up to 95%



Output Current: 1.5A



Current Mode Control



100% Duty Cycle in Dropout



Built-in Over Current Protection



Built-in Short Circuit Protection



Built-in Thermal Shutdown Protection



Built-in UVLO Function



Built-in Soft-start



Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)



Halogen and Antimony Free. “Green” Device (Note 3)

Pin Assignments

(Top View)

SOT25

Applications



LCD TV



Set-top Box



Datacom



Portable Device



Smart Phone

Notes:

1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.

2. See http://www.diodes.com/quality/lead_free.html

for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"

and Lead-free.

3. Halogen- and Antimony-

free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and

<1000ppm antimony compounds.

Typical Applications Circuit

AP3418-ADJ

L

C

IN

V

IN

R2

R1

4.7F

2.2

H

22F

EN

VIN

SW

FB

GND

1

4

3

2

5

1

2

3

4

5

EN

GND

SW

FB

VIN