Diodes AP3436/A - Manual

AP3436/A
Document number: DS37212 Rev. 2 - 2
1 of 15
www.diodes.com
April 2014
© Diodes Incorporated
AP3436/A
A Product Line of
Diodes Incorporated
3A, 1.25MHz High Performance Synchronous Buck Converter
Description
The AP3436/A is a step-down DC-DC converter with integrated
power stage capable of driving up to 3A continuous output current. It
integrates 2 N-channel power MOSFETs with low on-resistance.
Current mode control provides fast transient response and cycle-by-
cycle current limit.
For AP3436, the regulator adopts current-mode in forced pulse-width
modulation (PWM) mode with 1.25MHz switching frequency
internally, which allows small-sized components, such as capacitors
and inductors. This feature greatly simplifies the design of switch-
mode power supplies. Under PWM mode, the device remains at the
fixed PWM operation (typical at 1.25MHz), regardless of if the load
current is high or low.
For AP3436A, the regulator operates in either fixed PWM mode or a
pulse-skipping modulation (PSM) mode depending on the different
load conditions. The device can operate at typical 1.25MHz fixed
switching frequency under heavy load condition. At light load, the
regulator enters a PSM mode to minimize the switching loss by
reducing the switching frequency.
The AP3436/A provides EN function. Pulling this pin high statically
enables the device while pulling the pin low statically for longer than
10 μs will shut it down.
Under Voltage Lockout is internally set at 2.75V for V
CC
detection.
The output voltage startup ramp is controlled by the soft start. An
open drain power good signal indicates the output is within 75% to
125% of its nomin al voltage.
The AP3436/A is available in U-DFN3030-10 package.
Applications
 Desktop & Notebook

Low Voltage, High Density Power System

Consumer Application Such as Set Top Box, LCD Display and
CPE Equipment
Pin Assignments
(Top View)
U-DFN3030-10
Features

Analog Power Input V
CC
Range: 3.0V to 5.5V
 Power Input V
IN
Range: 1.3V to 5.5V
 0.6V Reference Voltage with ±1.5% Precision

2 MOSFETs (Typ 50m Ω) for High Efficiency at 3A Loads

High Efficiency: Up to 95%
 Output Current: 3A

Current Mode Control

Built-in Soft Start Function
 UV and OV Power Good Output
 Built-in UV and OV Protection Function

Built-in Over Current Protection

Built-in Thermal Shutdown Function
 Thermally Enhanced 3mm×3mm DFN Package

Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
 Halogen and Antimony Free. “Green” Device (Note 3)
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.
FB
GND
VCC
VIN
GND
SW
SW
BOOT
PGOOD
EN
Pin 1 Mark
1
2
3
4
5 6
7
8
9
10
11
EP