Page 1
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
Features
• Output voltage: 3.3V, 5V, 12V and adjustable output
version
• Adjustable version output vo l tag e range, 1.23V to
• 150Khz +
• Voltage mode non-synchronous PWM control
• Thermal-shutdown and current-limit protection
• ON/OFF shutdown control input
• Operating voltage can be up to 40V
• Output load current: 5A
• Low power standb y mode
• Built-in switching transistor on chip
• Lead Free packages: TO263-5L and TO220-5L(R)
• TO263-5L and TO220-5L(R): Available in “Green”
• Lead Free Finish/ RoHS Compliant (Note 1)
4%
37V+
Molding Compound (No Br, Sb)
15% fixed switching frequency
Applications
• Simple High-efficiency step-down regulator
• On-card switching regulators
• Positive to negative converter
Typical Application Circuit
(1) Fixed Type Circuit
General Description
The AP1501A series are monolithic ICs that are designed for a
step-down DC/DC converter, and possess the ability to drive a
5A load without additional transistor component. Due to reducing
the number of external component, the board space can be
saved easily. The external shutdown function can be controlled
by logic level and then come into standby mode. The internal
compensation makes feedback control have good line and load
regulation without external design. Regarding protected function,
thermal shutdown is to prevent over temperature operating from
damage, and current limit is against over current operating of the
output switch. The AP1501A series operates at a switching
frequency of 150Khz thus allowing smaller sized filter
components than what would be needed with lower frequency
switching regulators. Other features include a guaranteed
4% tolerance on output voltage under specified input voltage
+
and output load conditions, and +
The output version includes fixed 3.3V, 5V, 12V, and an
adjustable type. The packages are available in a standard 5-lead
TO263 and TO220 packages.
15% on the oscillator frequency.
12V
DC Input
Cin
Capacitor
12
Vin
4
AP1501A
-33
SD
FB
35
Gnd
Output
Inductor
D1
Schottky
Diode
L1
18uH
3.3V/5A
Output Load
Co
Capacitor
AP1501A Rev. 10 1 of 14 SEPTEMBER 2009
DS31191
www.diodes.com © Diodes Incorporated
Page 2
×
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
Typical Application Circuit (Continued)
(2) Adjustable Type Circuit
R2
FB
12V
DC Input
Cin
Capacitor
(3) Delay Start Circuit
12
Vin
V
V
R2 = 1K ~ 3K
AP1501A
SD
= V
out
= 1.23V
FB
4
Output
35
Gnd
R1
(1 +
FB
)
R2
R1
L1
22uH
D1
Schottky Diode
5V/ 5A
Output Load
Co
Capacitor
12V
DC Input
Cin
Capacitor
R2
FB
4
12
AP1501A
SD
R
DELAY
10K
C
DELAY
0.1uF
Vin
Output
35
Gnd
R1
L1
22uH
D1
Schottky Diode
5V/ 5A
Output Lo ad
Co
Capacitor
AP1501A Rev. 10 2 of 14 SEPTEMBER 2009
DS31191
www.diodes.com © Diodes Incorporated
Page 3
Ordering Information
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
AP1501A - XX
XXX X - X
Output Version
Blank : Adjustable
33 : 3.3V
50 : 5.0V
12 : 12V
Package
K5 : TO263-5L
T5 : TO220-5L
T5R : TO220-5L(R)
Lead Free
L : Lead Free
G : Green
Packing
U : Tube
13 : Tape & Reel
Device
Lead-free
AP1501A-XXK5L-U K5 TO263-5L 50 -U NA NA
Lead-free
AP1501A-XXK5L-13 K5 TO263-5L NA NA 800/Tape & Reel -13
AP1501A-XXK5G-U K5 TO263-5L 50 -U NA NA
AP1501A-XXK5G-13 K5 TO263-5L NA NA 800/Tape & Reel -13
AP1501A-XXT5L-U T5 TO220-5L 50 -U NA NA
Lead-free
AP1501A-XXT5G-U T5 TO220-5L 50 -U NA NA
AP1501A-XXT5RL-U T5R TO220-5L(R) 50 -U NA NA
Lead-free
AP1501A-XXT5RG-U T5R TO220-5L(R) 50 -U NA NA
Notes: 1. EU Directive 2002/95/ EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at
http://www.diodes.com/datasheets/ap02001.pdf.
http://www.diodes.com/products/lead_free.html
2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
Package
Code
Packaging
(Note 2)
Quantity Part Number
Tube 13” Tape and Reel
Quantity Part Number
Suffix
Suffix
Pin Assignments
( Top View )
( Top View )
5 SD
4 FB
3 Gnd
2 Output
1 V
IN
Metal Tab GND
TO263-5L
5 SD
4 FB
3 Gnd
2 Output
1 V
IN
TO220-5L/TO220-5L(R)
AP1501A Rev. 10 3 of 14 SEPTEMBER 2009
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Page 4
AP1501A
Pin Descriptions
Name Description
VIN Operating voltage input
Output Switching output
Gnd Ground
FB Output voltage feedback control
SD ON/OFF shutdown
Block Diagram
150KHz, 5A PWM BUCK DC/DC CONVERTER
SD
V
IN
220mV200mV
FB
Current
Source
bias
1.235V
Reference
+
_
Amp
2.5V
Regulator
Freq.
Compensation
_
Comp
+
Start
up
Comp
Comp
Pre-driver
+
_
_
+
5A
Switch
Output
150kHz
OSC.
Thermal
Shutdown
Gnd
AP1501A Rev. 10 4 of 14 SEPTEMBER 2009
DS31191
www.diodes.com © Diodes Incorporated
Page 5
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
Absolute Maximum Ratings
Symbol Parameter Rating Unit
ESD MM Machine Model ESD Protection 400 V
VCC Supply Voltage +45 V
VSD ON/OFF Pin input voltage -0.3 to +40 V
VFB Feedback Pin voltage -0.3 to +40 V
V
Output voltage to Ground -1 V
OUT
PD Power dissipation Internally limited W
TST Storage temperature -65 to +150
TJ Operating Junction Temperature -20 to +125
Recommended Operating Conditions
Symbol Parameter Rating Units
VOP Operating voltage 4.5 to 40 V
TA Operating Ambient Temperature -20 to 85
o
C
o
C
o
C
AP1501A Rev. 10 5 of 14 SEPTEMBER 2009
DS31191
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Page 6
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
Electrical Characteristics ( All Output Voltage Versions )
Unless otherwise specified, V
Specifications with boldface type are for full operating temperature range, the other type are for T
Symbol Parameter Conditions Min Typ. Max Unit
IFB Feedback Bias Current
F
Oscillator Frequency
OSC
V
Saturation Voltage
SAT
DC
Max. Duty Cycle(ON) V
Min. Duty Cycle(OFF) V
ICL Current Limit
Output = 0V
IL
Output = -1V V
IQ Quiescent Current V
I
STBY
VIL
VIH High (regulator OFF) 2.0
Standby Quiescent
Current
ON/OFF Pin Logic Input
Threshold Voltage
= 12V for 3.3V, 5V, adjustable version and V
IN
= 1.3V
V
FB
(Adjustable version only)
I
= 5A
OUT
no outside circuit
= 0V force driver on
V
FB
= 0V force driver on 100
FB
= 12V force driver of f 0
FB
peak current
no outside circuit
V
= 0 force driver on
FB
Output
Leakage
Current
no outside circuit
V
= 12 force driver off (Note 3)
FB
= 40V 2 60 mA
IN
= 12 force driver off 5 10 mA
FB
ON/OFF pin = 5V
= 40V
V
IN
Low (regulator ON)
= 24V for the 12V version. I
IN
J
40
127 150 173
110 173
1.5
5.5 6.0
200 uA
150
= 25ºC.
LOAD
1.3
= 0.5A
60
100
Khz
1.6
1.7
6.5
7.5
250
300
0.6
nA
V
%
A
uA
V
ON/OFF Pin Logic
IH
Input Current
ON/OFF Pin Input
IL
Current
θ
θ
Notes: 3. Feedback pin removed from output and connected to 0V to force the output transistor switch ON. Feedback pin removed from output
and connected to 12V for the 3.3V, 5V, and the ADJ. version, and 15V for the 12V version, to force the output transistor switch OFF.
4. Test condition: Device mounted with copper area of approximately 3in
Thermal Resistance
JA
Junction-to-Ambient
Thermal Resistance
JC
Junction-to-Case
V
= 2.5V (OFF) 15 25
LOGIC
V
= 0.5V (ON) 0.02 5
LOGIC
TO263-5L (Note 4) 37
o
TO220-5L(R) (Note 4) 31
TO263-5L (Note 4) 6
o
TO220-5L(R) (Note 4) 5
2
, 1oz, no air flow.
uA
C/W
C/W
AP1501A Rev. 10 6 of 14 SEPTEMBER 2009
DS31191
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Page 7
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
Electrical Characteristics ( Continued )
Specifications with boldface type are for full operating temperature range, the other type are for TJ = 25ºC.
AP1501A-ADJ
AP1501A-3.3V
AP1501A-5V
AP1501A-12V
Symbol Parameter Conditions Typ. Limit Unit
5V <
V
FB
η
V
OUT
η
V
OUT
η
V
OUT
η
Output
Feedback
Efficiency V
Output Voltage
Efficiency V
Output Voltage
Efficiency V
Output Voltage
Efficiency V
VIN < 40V
0.2A <
I
< 5A
LOAD
programmed for 3V
V
OUT
= 12V, I
IN
5.5V <
0.2A <
= 12V, I
IN
8V <
0.2A <
= 12V, I
IN
15V <
0.2A <
= 16V, I
IN
LOAD
VIN < 40V
I
< 5A
LOAD
LOAD
VIN < 40V
I
< 5A
LOAD
LOAD
VIN < 40V
I
< 5A
LOAD
LOAD
1.23
=5A 72 %
3.3
=5A 71 %
= 5A 78 %
12
= 5A 88 %
5
1.193/1.18
1.267/1.28
3.168/3.135
3.432/3.465
4.8/4.75
5.2/5.25
11.52/
12.48/
11.4
12.6
V
V
MIN
V
MAX
V
V
MIN
V
MAX
V
V
MIN
V
MAX
V
V
MIN
V
MAX
AP1501A Rev. 10 7 of 14 SEPTEMBER 2009
DS31191
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Page 8
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
Typical Performance Characteristics
Typical Performance Characteristics
Normalized Output Voltage
Efficiency
5.10
5.05
5.00
4.95
OUTPUT VOLTAGE CHANGE
4.90
1.7
1.6
1.5
1.4
SATURATION VOLTAGE (V)
1.3
1.2
VIN=20V, I
Normalized at T
-50 -25 0 25 50 75 100 125
JUNCTION TEMPERA TU RE(°C)
LOAD
=3A
= 25°C
J
Switch Saturation Voltage
1 : -40oC
o
C
2 : 25
o
3 : 125
C
1
2
3
2.0
SWITCH CURRENT(A)
3
45
100
95
90
85
5V
80
EFFICIENCY (%)
75
3.3V
70
65
8101520253035
INPUT VOLTAGE
5A Load
40
Switch Current Limit
7.5
VIN=12V, V
7.0
6.5
SWITCH CURRENT LIMIT (A)
6.0
5.5
-50 -25 0 25 50 75 100 125
JUNCTION TEMPERATURE(°C)
OUT
=5V
Operating Quiescent Current
25.0
20.0
15.0
10.0
SUPPLY CURRENT (mA )
5.0
0.0
-50 -25 0 25 50 75 100 125
JUNCTION TEMPERATURE(°C)
Switch ON
Switch OFF
200.0
160.0
120.0
80.0
CURRENT (uA)
40.0
Shutdown Quiescent Current
1
2
3
0.0
10 20 30 40
SUPPLY VOLTAGE (V)
V
ON/OFF
1 : -40
2 : 25
3 : 125
o
o
=5V
C
C
o
C
AP1501A Rev. 10 8 of 14 SEPTEMBER 2009
DS31191
www.diodes.com © Diodes Incorporated
Page 9
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
Typical Performance Characteristics (Continued)
Minimum Operating Supply Voltage
5.0
5.0
ON/OFF Threshold Voltage
4.0
3.0
2.0
V
1.0
SUPPLY VOLTAGE (V)
0.0
OUT
I
LOAD
-50 -25 0 25 50 75 100 125
JUNCTION TEMPERATURE (oC)
ON/OFF Pin Current (Sinking)
150.0
120.0
90.0
60.0
CURRENT (uA)
30.0
VIN=40V
-40
0.0
1.45 10152022232425
=1.23V
=120mA
o
C TJ 125oC
≤≤
ON/OFF PIN VOLTAGE (V)
4.0
3.0
2.0
1.0
THRESHOLD VOLTAGE (V)
0.0
-50
0
-25
JUNCTION TEMPERATURE (oC)
Switch Frequency
200.0
150.0
100.0
50.0
FREQUENCY (kHz)
0.0
-50 -25 0 25 50 75 100 125
JUNCTION TEMPERATURE (oC)
25 50 75
100 125
Feedback Pin Bias Current
50.0
40.0
30.0
20.0
Adjustable Version Only
BIAS CURRENT (nA)
10.0
0.0
-50 -25 0 25 50 75 100 125
o
JUNCTION TEMPERATURE(
C)
AP1501A Rev. 10 9 of 14 SEPTEMBER 2009
DS31191
www.diodes.com © Diodes Incorporated
Page 10
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
Functional Description
Pin Functions
+V
IN
This is the positive input supply for the IC switching regulator. A suitable
input bypass capacitor must be present at this pin to minimize voltage
transients and to supply the switching currents needed by the regulator.
Ground
Circuit ground.
Output
Internal switch. The voltage at this pin switches between (+V
and approximately – 0.5V, with a duty cycle of approximately
/ VIN. To minimize coupling to sensitive circuitry, the PC board
V
OUT
copper area connected to this pin should be kept a mini mum.
Feedback
Senses the regulated output voltage to complete the fee dback loop.
ON/OFF
Allows the switching regulator circuit to be shutdown using logic level
signals thus dropping the total input supply current to approximately
150uA. Pulling this pin below a threshold voltage of approximately
1.3V turns the regulator on, and pulling this pin above 1.3V (up to a
maximum of 40V) shuts the regulator down. If this shutdown feature is
not needed, the ON/OFF pin can be wired to the ground pin or it can be
left open, in either case the regulator will be in the ON condition.
Thermal Considerations
The AP1501A is available in two packages, a 5-pin surface mount
TO-263 and TO-220.
The TO-220 package needs a heat sink under mo st conditions. The size
of the heat sink depends on the input voltage, the output voltage, the
load current and the ambient temperature. The AP1501A junction
temperature rises above ambient temperature for a 5A load a nd different
input and output voltages. The data for these curves was taken with the
AP1501A (TO-220 package) operating as a buck switching regulator in
an ambient temperature of 25
numbers are all approximate and there are many factors that can affect
these temperatures. Higher ambient temperatures require more heat
sinking.
The TO-263 surface mount package tab is designed to be soldered to
the copper on a printed circuit board. The copper and the board are the
heat sink for this package and the other heat producing components,
such as the catch diode and inductor. The PC board copper area that
the package is soldered to should be at least 0.8 in
have 2 or more square inches of 2 oz. Additional copper area improves
the thermal characteristics, but with copper areas greater than
approximately 6 in
realized. If further thermal improvements are needed, double sided,
multilayer PC boards with large copper areas and/or airflow are
recommended.
2
, only small improvements in heat dissipation are
o
C (still air). These temperature rise
2
, and ideally should
IN
– V
SAT
)
The AP1501A (TO-263 package) junction temperature rise above
ambient temperature with a 2A load for various input and output voltages.
This data was taken with the circuit operating as a buck switching
regulator with all components mounted on a PC board to simulate the
junction temperature under actual operating conditions. This curve can
be used for a quick c heck for the a pproximate j unction temp erature for
various conditions, but be aware that there are many factors that can
affect the junction temperature. When load currents higher than 3A are
used, double sided or multilayer PC boards with large copper areas
and/or airflow might be needed, especially for high ambient te mperatures
and high output voltages.
For the best thermal performance, wide copper traces and generous
amounts of printed circuit board copper should be used in the board
layout. (Once exception to this is the output (switch) pin, w hich should not
have large areas of copper.) Large areas of copper provide the best
transfer of heat (lower thermal resistance) to the surrounding air, and
moving air lowers the thermal resistance even furthe r.
Package thermal resistance and junction temperature rise numbers are
all approximate, and there are many factors that will affect these
numbers. Some of these factors include board size, shape, thickness,
position, location, and even board temperatu re. Other factors are, trace
width, total printed circuit copper area, copper thickness, single or
double-sided, multilayer board and the amount of solder on the board.
The effectiveness of the PC board to dissipate heat al so depends on the
size, quantity and spacing of other components on the board, as well as
whether the surrounding air is still or moving.
Furthermore, some of these components such as the catch diode will
add heat to the PC board and the heat can vary as the input voltage
changes. For the inductor, depending on the physical size, type of core
material and the DC resistance, it could either act as a heat sink taking
heat away from the board, or it could add heat to the board.
AP1501A Rev. 10 10 of 14 SEPTEMBER 2009
DS31191
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Page 11
Marking Information
(1) TO263-5L
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
( Top View )
Logo
Output Type :
1501A : ADJ
1501A33 : 3.3V
1501A50 : 5.0V
1501A12 : 12V
(2) TO220-5L(R)
Output Type :
1501A : ADJ
1501A33 : 3.3V
1501A50 : 5.0V
1501A12 : 12V
1501A XX
YY WW
( Top View )
X
1501AXX
YY WW X X
X
L : Lead Free
G : Green
ID code
Xth week : 01~52
Year :
"08" = 2008
"09" = 2009
~
Logo
L : Lead Free
G : Green
ID code
Xth week: 01~52
Year:
"08" = 2008
"09" = 2009
~
AP1501A Rev. 10 11 of 14 SEPTEMBER 2009
DS31191
www.diodes.com © Diodes Incorporated
Page 12
150KHz, 5A PWM BUCK DC/DC CONVERTER
Package Information (All Dimensions in mm)
(1) Package Type: TO263-5L
AP1501A
(2) Package Type: TO220-5L
AP1501A Rev. 10 12 of 14 SEPTEMBER 2009
DS31191
www.diodes.com © Diodes Incorporated
Page 13
150KHz, 5A PWM BUCK DC/DC CONVERTER
Package Information (Continued)
(3) Package Type: TO220-5L(R) Mechanical drawing
AP1501A
AP1501A Rev. 10 13 of 14 SEPTEMBER 2009
DS31191
www.diodes.com © Diodes Incorporated
Page 14
AP1501A
150KHz, 5A PWM BUCK DC/DC CONVERTER
IMPORTANT NOTICE
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS
DOCUMENT, INCLUDING, BU T NOT LIMI TED TO, T HE IMPLIE D WARRANT IES OF ME RCHANTABILIT Y AND FI TNESS FOR A
PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other
changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any
liability arisi ng out of the application or use of this document or any product descr ibed herein; neither does Diode s Incorporated
convey any license under its patent or trademark rig hts, nor the rights of othe rs. Any Customer or user of this docume nt or products
described herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the
companies whose products are represented on Diodes Incorporated website, harmless against all damages.
Diodes Incorporat ed does not warrant or accept a ny liabil ity whatsoeve r in respect of any p roducts purc hase d through unau thori zed
sales channel.
Should Customers purch ase or use Diodes Incorpo rated products for an y unintended or unau thorized applic ation, Customers sh all
indemnify and hold Dio des Inc orporated and its re presen tatives harmle ss against all cla ims, d amages, expens es, a nd attor ney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized
application.
Products described here in may be covered by one or more Unit ed States, i nternationa l or foreign patents p ending. Product n ames
and markings noted herein may also be covered by one or more United States, i nte rnational or foreign trademarks.
LIFE SUPPORT
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems
without the express written approval of the Chief Executi ve Off icer of Diodes Incorporate d. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided
in the labeling can be reasonably expected to result in significant injury to the user.
B. A critic al comp onent is any com ponent i n a life suppor t devic e or system whose f ailure to pe rform ca n be reasonabl y expect ed
to cause the failure of the life support device or to affect its safety or effectiveness.
Customers repres ent that th ey have all necessar y expertis e in th e safety a nd regul ator y ramific ations of t heir lif e support devic es or
systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements
concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems,
notwithstandin g any devices- or systems-related i nformation or support that may be provided by Diod es Incorporated. Further,
Customers must full y indemnify Diode s Incorporat ed and its represent atives ag ainst any damages ari sing out of th e use of Diodes
Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2009, Diodes Incorporated
www.diodes.com
AP1501A Rev. 10 14 of 14 SEPTEMBER 2009
DS31191
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