AP3428/A

Document number: DS37417 Rev. 5 - 2

1 of 14

www.diodes.com

May 2021

© 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

only 40μA of no-load quiescent current. Ultra-low RDS(ON) integrated

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, TSOT25 (Type SM), U-

DFN2020-6 (Type J) packages.

Features



Output Current: Up to 1A



Output Voltage: 0.6V to VIN



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



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



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



For automotive applications requiring specific change

control (i.e. parts qualified to AEC-Q100/101/200, PPAP

capable, and manufactured in IATF 16949 certified facilities),

please contact us or your local Diodes representative.

https://www.diodes.com/quality/product-definitions/

Pin Assignments

(Top View)

TSOT25/TSOT25 (Type SM) for AP3428

(Top View)

TSOT25/TSOT25 (Type SM) 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) & 2015/863/EU (RoHS 3) compliant.

2. See https://www.diodes.com/quality/lead-

free/ 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.