Diodes AP3440 User Manual
Ap3440, Description, Applications
AP3440
Document number: DS36691 Rev. 2 - 2
1 of 15
March 2014
© Diodes Incorporated
AP3440
A Product Line of
Diodes Incorporated
N
E
W
P
R
O
D
U
C
T
4A, 2MHZ HIGH PERFORMANCE SYNCHRONOUS BUCK CONVERTER
Description
The AP3440 is a current mode, PWM synchronous buck (step-down)
DC-DC converter, capable of driving a 4A load with high efficiency,
excellent line and load regulation.
The device integrates two N-channel power MOSFETs with low on-
resistance. Current mode control provides fast transient response and
cycle-by-cycle current limit.
The switching frequency of AP3440 can be programmable from
200kHz to 2MHz, which allows small-sized components, such as
capacitors and inductors. A standard series of inductors from several
different manufacturers are available. This feature greatly simplifies
the design of switch-mode power supplies.
Under voltage lockout is internally set at 2.6V, but can be increased
by programming the threshold with a resistor network on the enable
pin. The output voltage startup ramp is controlled by the soft-start pin.
An open drain power good signal indicates the output is within 93% to
107% of its nominal voltage.
The AP3440 is available in U-QFN3030-16 package.
Applications
Low-voltage, High-density Power Systems
Point of Load Regulation for High Performance DSPs, FPGAs,
ASICs and Microprocessors
Broadband,
Networking
and
Optical
Communications
Infrastructure
Pin Assignments
(Top View)
VIN
VIN
GND
GND
A
G
N
D
F
B
C
O
M
P
R
T
/C
L
K
SS
SW
SW
SW
B
O
O
T
P
G
D
E
N
V
IN
E P
5
6
7
8
1
2
3
4
9
12
Pin 1 Mark
11
10
13
14
15
16
U-QFN3030-16
Features
Input Voltage Range: 2.95V to 5.5V
0.8V Reference Voltage with ±3% Precision
Two 30m
(Typical) MOSFETs for High Efficiency at 4A Load
High Efficiency: Up to 94%
Output Current: 4A
Programmable Frequency:200kHz to 2MHz
Current Mode Control
Synchronizes to External Clock
Adjustable Soft-start
Soft Start-up into Pre-biased Output
UV and OV Power Good Output
Built-in Over Current Protection
Built-in Thermal Shutdown Function
Programmable UVLO Function
Built-in Over Voltage Protection
Thermally Enhanced 3mm×3mm 16-pin U-QFN3030-16
Totally Lead-free & Fully RoHS Compliant (Note1 & 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
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.