AP3405

Document number: DS38093 Rev. 1 - 2

1 of 9

www.diodes.com

January 2016

© Diodes Incorporated

AP3405

600mA Step-down DC/DC Converter with Synchronous Rectifier

Description

The AP3405 is a 2.0MHz fixed frequency, current mode, PWM

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

600mA load with high efficiency, excellent line and load regulation.

The high efficiency is easily configured by using an inductor, resistors

and capacitors as the external components. Current mode control

provides fast transient response and cycle-by-cycle current limit.

The AP3405 employs complete protection to ensure system security,

including input Undervoltage Lockout, Over-Temperature Protection

and hiccup mode Short Circuit Protection.

This IC is available in U-DFN2020-8 package.

Features



High-Efficiency Buck Power Converter



Input Voltage Range: 2.3V to 5.5V



Output Voltage Range: 0.7V to 5.5V



Fixed 2.0MHz Oscillator Frequency



Built-in Soft-Start Time



Built-in Overcurrent Protection



Built-in Thermal Shutdown Function



Built-in UVLO Function



Hiccup Mode SCP



Output Current: 600mA



Package: U-DFN2020-8 (Type E)



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



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

Pin Assignments

(Top View)

1

Pin 1 Mark

2

4

8

7

5

EP

NC

NC

PGND

EN

FB

SW

3

6

AGND

VIN

U-DFN2020-8 (Type E)

Applications



Post DC-DC Voltage Regulation



Mobile Phones and Wearable Devices

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 Diod

es 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

L 2.2

μH

4.7

μF

ON/OFF

VIN

EN

SW

FB

AGND

PGND

10

μF

R1

240K

Ω

R2

120K

Ω

22pF

AP3405

8

3

4

5

6

7