Diodes AP3431 User Manual
Data sheet, General description, Features

 
 
Data Sheet
1.0MHz, 2.0A, Synchronous Step Down DC-DC Converter AP3431
Nov. 2011 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
1
 
 
 
 
 
General Description 
The AP3431 is a high efficiency step-down DC-DC 
voltage converter. The chip operation is optimized 
by peak-current mode architecture with built-in 
synchronous power MOS switchers. The oscillator 
and timing capacitors are all built-in providing an 
internal switching frequency of 1MHz that allows 
the use of small surface mount inductors and 
capacitors for portable product implementations. 
Integrated Soft Start (SS), Under Voltage Lock Out 
(UVLO), Thermal Shutdown Detection (TSD) and 
short circuit protection are designed to provide 
reliable product applications. 
The device is available in adjustable output voltage 
versions ranging fro
m 0.8V to 0.9×V
IN
when input
voltage range is from 2.7V to 5.5V , and is able to 
deliver up to 2.0A. 
 
The AP3431 is available in SOIC-8 package. 
 
 
 
 
 
 
 
Features
 
• High Efficiency Buck Power Converter 
• Output Current: 2A 
• Low R
DS(ON)
Internal Switches : 120m
Ω(V
IN
=5V)
• Adjustable Output Voltage from 0.8V to 0.9×V
IN
• Wide Operating Voltage Range: 2.7V to 5.5V
•
Built-in Power Switches for Synchronous
Rectification with High Efficiency
• Feedback Voltage: 800mV 
• Switching Frequency: 1.0MHz 
• Thermal Shutdown Protection 
• Internal Soft Start 
 
 
Applications
• LCD TV 
• Set Top Box 
• Post DC-DC Voltage Regulation 
• PDA and Notebook Computer 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 1. Package Type of AP3431 
 
SOIC-8
