AP3428/A

Document number: DS37417 Rev. 2 - 2

1 of 13

www.diodes.com

June 2016

© Diodes Incorporated

AP3428/A

1.5MHZ, 1A STEP-DOWN DC-DC BUCK CONVERTER

Description

The AP3428/A is a 1A step-down DC-DC converter. At heavy load,

the constant-frequency PWM control performs excellent stability and

transient response. No external compensation components are

required.

The AP3428/A supports a range of input voltages from 2.5V to 5.5V,

allowing the use of a single Li+/Li-polymer cell, multiple Alkaline/NiMH

cell, and other standard power sources. The output voltage is

adjustable from 0.6V to the input voltage. The AP3428/A employs

internal power switch and synchronous rectifier to minimize external

part count and realize high efficiency. During shutdown, the input is

disconnected from the output and the shutdown current is less than

1μA. Other key features include over-temperature and short circuit

protection, and under-voltage lockout to prevent deep battery

discharge.

The AP3428/A delivers 1A maximum output current while consuming

MOSFETs and 100% duty cycle operation make the AP3428/A an

ideal choice for high output voltage, high current applications which

require a low dropout threshold. Pulse skip mode allows to maintain

high efficiency at light-load conditions.

The AP3428/A is available in TSOT25, U-DFN2020-6 (Type J)

packages.

Features



Output Current: Up to 1A





Input Voltage: 2.5V to 5.5V



0.6V Reference Voltage With ±2% Precision



40µA (Typ) No Load Quiescent Current



Shutdown Current: <1µA



100% Duty Cycle Operation



1.5MHz Switching Frequency



Internal Soft Start



No External Compensation Required



Current Limit Protection



Thermal Shutdown



TSOT25, U-DFN2020-6 (Type J) Packages



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



Halogen

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

Pin Assignments

(Top View)

TSOT25 for AP3428

(Top View)

TSOT25 for AP3428A

(Top View)

U-DFN2020-6 (Type J)

Applications



Post DC-DC Voltage Regulation



Set Top Boxes



Notebook Computer



PAD

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 ab

out 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.

NC

EN

VIN

FB

GND

LX

P in 1 Mark

1

2

3

4

5

6

1

2

3

4

5

EN

GND

LX

FB

VIN

1

2

3

4

5

EN

GND

LX

FB

VIN