AP1509
150kHz, 2A PWM BUCK DC-DC CONVERTER
Description
The AP1509 series are monolithic ICs designed for a step-down
DC-DC converter and have the ability of driving a 2A load without an
additional transistor, which saves board space.
The external shutdown function can be controlled by logic level and
then go
into standby mode. The internal compensation makes
feedback control have
good line and load regulation without external
design. Regarding protected function, thermal shutdown prevents
overtemperature operating from damage, and current limit works
against overcurrent operating of the output switch.
If current limit
function occurs, and VFB is below 0.5V, the switching frequency is
reduced. The AP15
09 series operates at a switching frequency of
150kHz thus allowing smaller-sized filter components than what is
required with lower frequency s witching regul ators.
Other features include a guaranteed +4% tolerance on output voltage
under specified input voltage and output load conditions, and +15%
on the oscillator frequency. The output version included fixed 3.3V,
5V, 12V, and an adjustable type. The chip
s are available in a
standard 8-lead SO-8 package.
Pin Assignme nts
(Top View)
1
2
3
4
8
7
6
5
V
IN
GND
FB AP1509
GND
Output
GND
GND
SD
SOP-8L
Features
• Output Voltage: 3.3V, 5V, 12V, and Adjustable Output Versi on
• Adjustable Versi on Output Volt age Range of 1.23V to 18V+4%
• 150kHz +15% Fixed Switching F requency
• Voltage Mode Non-Synchronous PWM Control
• Thermal-Shutdown and Current-Limit Protection
• ON/OFF Shutdown Control Input
• Operating Voltage up to 22V
• Output Load Current: 2A
• Low Power Standby Mode
• Built-in Switching Transistor On Chip
• Totally Lead-Free & Fully RoHS Com pliant (Note 1 & 2)
• Halogen and Antimony Free. “Green” Devi ce (Note 3)
Applications
• Simple High-Effici ency Step-Down Regulat or
• On-Card Switching Regulators
• Positive to Negative Converter
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.
AP1509
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AP1509
Typical Application Circuit
(1) Fixed Type Circuit
1 2
8
4
3
12V
DC Input
C
IN
Capacitor
FB
SD D1
Schottky Diode
V
IN
GND
Output
AP1509-
33
Co
Capacitor
Inductor
L1
47uH 3.3V/2A
Output Load
GNDGND
GND
5 6 7
(2) Adjustable Type Circuit
1 2
8
4
3
12V
DC Input
CIN
Capacitor
FB
SD D1
Schottky
Diode
VIN
GND
Output
AP1509
Co
Capacitor
Inductor
L1
39uH 2.5V/2A
Output Load
GNDGNDGND
5 6 7
R1 1KR2 1K
VOUT = VFB × (1 +
R2
R1
)
VFB = 1.23V
R2 = 1K ~ 3K
(3) Delay Start Circui t
1 2
8
4
3
12V
DC Input
C
IN
Capacitor
FB
SD D1
Schottky
Diode
V
IN
GND
Output
AP1509
Co
Capacitor
Inductor
L1
39uH 2.5V/2A
Output Load
GND
GNDGND
5 6 7
R1 1K
R2 1K
C
DELAY
0.1uF
10K
R
DELAY
AP1509
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AP1509
Pin Descriptions
Functional Bloc k Diagram
Current
Source
bias
1.235V
Reference 2.5V
Regulator
150kH
z
OSC.
Start
up
+
+
_
+
_
Thermal
Shutdown
Pre-
driver
Comp
Comp
GND
Output
V
IN
SD
FB
220mV
200mV
2A
Switch
+
_
_
Amp Comp
Frequecy
compen-
sation
Pin Name Description
VIN Operating Voltage Input
Output Switching Output
GND Ground
FB Output Voltage Feedback Control
SD ON/OFF Shutdown
AP1509
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AP1509
Absolute Maximum Ratings
Symbol Parameter Rating Unit
ESD HBM Human Body Model ESD Protection
2
KV
ESD MM Machine Model ESD Protection 200 V
VIN Supply Voltage +24 V
VSD ON/OFF Pin Input Voltage -0.3 to +18 V
VFB Feedback Pin Voltage -0.3 to +18 V
VOUT Output Volt age to Ground -1 V
PD Power Dissipation Internally Limited W
TST Storage Temperature -65 to +150 °C
TJ Operating Junction Temperature -40 to +125 °C
Recommended Operating Conditions
Symbol Parameter Min Max Unit
OUT
Output Current
0
2
A
OP
Operating Voltage
4.5
22
V
TA Operating Ambient Temperature -20 85 °C
AP1509
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AP1509
Electrical Characteristics
Unless otherwise s pecified, VIN = 12V for 3.3V, 5V, adjustable version, and VIN = 18V for the 12V version. ILOAD = 0 .5A
Specificat i ons with bold face type are for full operati ng tem perat ure range, t he other type are for TJ = 25 °C.
Symbol
Parameter
Conditions
Min
Typ.
Max
Unit
IFB Feedback Bias Current
V
FB
= 1.3V
(Adjustable Version Only)
— -10
-50
nA
-100
FOSC Oscil l at or Frequency —
127
150
173
kHz
110
173
FSCP
Oscillator Frequency of Short Circuit
Protect
When Current Limit Occurred and
VFB < 0.5V, Ta = 25 °C
10 30 50 kHz
VSAT Saturation Voltage IOUT = 2 A
No Outside Circuit
VFB = 0V Force Driver On
— 1.25
1.4
V
1.5
DC
Max. Duty Cycle (ON)
VFB = 0V Force Driver On
—
100
—
%
Min. Dut y C ycle (OFF)
VFB = 12V Force Dri ver Off
—
0
—
ICL Current Limit
Peak Current
No Outside Circuit
VFB = 0V Force Driver On
3 — — A
IL Output = 0 Output Leakage Current
No Outside Circuit
VFB = 12V Force Dri ver Off
— — -200 µA
Output = -1
VIN = 22V
—
-5
mA
IQ
Quiescent Current
VFB = 12V Force Dri ver Off
—
5
10
mA
ISTBY Standby Quiescent Current
ON/OFF pin = 5V
VIN = 22V
— 70
150
µA
200
VIL
ON/OFF Pin Logic Input Threshold
Voltage
Low (Regulator ON)
—
1.3
0.6
V
VIH High (Regulator OFF) 2.0 —
IH
ON/OFF Pin Logic Input Current
VLOGIC = 2.5V (OF F)
—
—
-0.01
µA
IL
ON/OFF Pin Input Current
VLOGIC = 0.5V (ON)
—
-0.1
-1
ϴJA
Thermal Resistanc e
SO-8
Junction to Case
—
15
—
°C/W
ϴJC
Thermal Resistanc e
with a Copper Area of Approximately
3in
2
SO-8 Junction to Ambient — 70 — °C/W
AP1509 - ADJ VFB Output
Feedback
4.5V < V
IN
< 2 2V
0.2A < ILOAD < 2A
VOUT Programmed for 3V
1.193
1.18 1.23 1.267
1.28 V
Ƞ
Efficiency VIN = 12V, ILOAD=2A 76 76 — %
AP1509 - 3.3V VOUT Output Voltage
4.75V < V
IN
< 2 2V
0.2A < ILOAD < 2A
3.168
3.135 3.3
3.432
3.465 V
Ƞ Efficiency VIN = 12V,
ILOAD = 2A
78 78 — %
AP1509 - 5V VOUT Output Voltage
7V < V
IN
< 22V
0.2A < ILOAD < 2A
4.8
4.75
5
5.2
5.25
V
Ƞ Efficiency
V
IN
= 12V,
ILOAD = 2A
83 83 — %
AP1509 - 12V VOUT Output Voltage
15V < V
IN
< 22V
0.2A < ILOAD < 2A
11.52
11.4 12
12.48
12.6 V
Ƞ Efficiency
V
IN
= 15V,
ILOAD = 2A
90 90 — %
AP1509
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AP1509
Typi cal Perfo rmance Char act eristics
AP1509 Efficiency vs. Temperature
(VIN = 12V, VOUT = 5V, I o = 2A)
75
76
77
78
79
80
81
82
83
84
85
86
-50 -30 -10 10 30 50 70 90 110 130 150
Temperat ure (T
A) (°C)
Efficiency (%)
AP1509 Efficiency vs. Temperature
(VIN = 12V, VOUT = 3.3V, Io = 2A)
73
74
75
76
77
78
79
80
81
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (T
A) (°C)
Efficiency (%)
AP1509 Saturation Voltage vs. Temperatu re
(VIN = 12V, VFB = 0V, VSD = 0)
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
-50 -25 025 50 75 100 125
Temperature (TA)　(°C)
Saturat ion Voltage ( V )
2A
1A
0.5A
AP1509 Switch Curr ent Limit vs. Temperatur e
(VIN = 12V, VFB = 0V)
3
3.5
4
4.5
5
5.5
-50 -30 -10 10 30 50 70 90
Temperature (TA) (°C)
Switch Current Limit (A)
AP1509 Supply Current vs. Temperature
(VIN = 12V, No Load, Von/off = 0V (Swi tch ON) ,Von/o ff = 5V (Switch O F F ))
5
6
7
8
9
10
11
12
13
14
15
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (°C)
Supply Current (mA)
Switch ON
30
35
40
45
50
55
60
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (°C)
Supply Current (uA)
Switch OF F
AP1509
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AP1509
Typi cal Perfo rmance Char act eristics (continued)
AP1509 Thresh o l d Voltage vs. Temperature
(VIN = 12V, Io = 100mA)
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (°C)
Threshold Voltage (V)
AP1509 ON/OFF Current vs. ON/OFF Voltage
(VIN = 12V)
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
0 3 6 9 12 15 18 21
ON/OFF Voltage (V)
ON/OFF Current (nA)
AP1509 F r eq uen cy vs. Temperatur e
(VIN = 12V, Io = 500mA, VOUT = 5V)
140
145
150
155
160
165
170
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (°C)
Frequency (KHz)
AP1509 F eed b ack Cur r ent vs. Temper atur e
(VIN = 12V, VOUT = 5V, Vfb = 1.3V)
-50
-40
-30
-20
-10
0
10
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature (TA) (°C)
Feedback Current (nA)
AP1509 O u tpu t Voltage vs. Temperature
(VIN = 12V, Io = 2A)
2.9
2.95
3
3.05
3.1
3.15
3.2
3.25
3.3
3.35
3.4
3.45
3.5
-40 -20 020 40 60 80 100 120 140 160
Temperature (TA) (°C)
V
OUT
(V)
AP1509
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AP1509
Typi cal Perfo rmance Char act eristics (continued)
Header Frequency vs. Temperature
Feedback Voltage vs. Temperature
(VIN = 15V, VOUT = 5V)
0
100
200
300
400
500
600
700
800
900
1000
-40 10 60 110
Frequency (KHz)
Temperature (
o
C)
1.22
1.23
1.24
1.25
1.26
-40 10 60 110
Feedback Voltage (V)
Temperature (
o
C)
Suppl y Current vs. Temperature
(VIN = 15V, VOUT = 5V, lOUT = 0A)
Supply Current vs. Supply Voltage
(VIN = 15V, VOUT = 5V, lOUT = 0A)
0
0.5
1
1.5
2
2.5
3
-40 10 60 110
Supply Current (mA)
Temperature (
o
C)
0
0.5
1
1.5
2
2.5
3
0 5 10 15
Supply Current (mA)
Supply Voltage (V)
Efficien cy vs. Output Current
(VIN = 15V, VOUT = 5V)
Efficien cy vs. Output Current
(VIN = 15V, VOUT = 3.3V)
70
75
80
85
90
020 40 60
Ef f iciency (%)
O utput Cur r ent (mA)
55
65
75
85
020 40 60
Ef f iciency (%)
O utput Cur r ent (mA)
AP1509
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AP1509
Functions Description
Pin Functions
+VIN
This is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be presented at this pin to minimize
voltage trans i ents and to supply the switchi ng currents required by the regulator.
Ground
Circuit ground.
Output
Internal s witch. T he voltage at this pi n s witches between (+VIN - VSAT) and approximately -0.5V with a duty cycle of approximat el y VOUT/VIN.
To minimize coupling to sensitive circuitry, the PCB copper area connected to this pin should be minimized.
Feedback
This pin senses the regulated output voltage to compl ete the feedback loop.
SD
Allows the switching regulat or circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately
150µA. 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 18V) shuts the regulator down. If this shutdown feature is not required, the SD pin can be wired to the ground pin.
Thermal Considerations
The SO-8 package requires a heat sink under most conditi ons. The size of the heat sink depends on the input voltage, the output voltage,
the load current, and the ambient temperature. The AP1509 junction temperature rises above ambient temperature for a 2A load and
different input and output voltages. The data for these curves was taken with the AP1509 (SO-8 package) operating as a buck-switching
regulator in an am bient temperature of 25°C (st ill air). These temperature i ncrements are all approximate and are af fected by m any factors.
Higher ambient temperat ures require more heat sinker.
For the best thermal performance, wide copper traces and generous amounts of PCB copper should be used in the board layout; one
exception is t he output (switch) pin, which should not have large areas of copper. Large areas of copper provide the best trans fer of heat
(lower thermal resist ance) to the surrounding air and moving air lowers the thermal resistance even further.
Package therm al resist ance and junction temperature increments are al l approximate. The i ncrem ents are aff ected by a lot of factors. Some
of these factors include board size, shape, thickness, position, location, and even board temperature. Other factors are, trace width, total
printed ci rcuit copper area, copper t hickness, single or double-sided, multi-layer board, and the amount of solder on the board.
The effectiveness of the PCB t o dissipate heat also 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, add heat to the PCB,
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
resistanc e, it could either act as a heat sink taking heat away from the board, or it could add heat to the board.
AP1509
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AP1509
Ordering Information
Device Voltage
(V) Package
Code Package
(Note 5) Lead
Free/Green Quantity
Part Number Suffix
Status
(Note 4) Alternative
Tube
13” Tape
and Reel
AP1509-12SG-13
12
S
SO-8
Green
2500
NA
-13
In production
AP1509-33SG-13
3.3
S
SO-8
Green
2500
NA
-13
In production
AP1509-50SG-13
5.0
S
SO-8
Green
2500
NA
-13
In production
AP1509-SG-13
ADJ
S
SO-8
Green
2500
NA
-13
In production
AP1509-12SGL-13
12
S
SO-8
Green
2500
NA
-13
End of life
None
AP1509-33SGL-13 3.3 S SO-8 Green 2500 NA -13 End of life None
AP1509-50SGL-13 5.0 S SO-8 Green 2500 NA -13 End of life None
AP1509-SGL-13
ADJ
S
SO-8
Green
2500
NA
-13
End of life
None
Notes: 4. All Lead-free versions are End of Life (EOL) with no replac em ent .
5. For packaging details, go to our website at:
https://www.diodes.com/design/support/packaging/diodes-packaging/diodes-package-outlines-and-pad-layouts/
Marking Information
(1) SO-8
AP1509
Document number: DS31016 Rev. 5 - 2 10 of 12
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AP1509
Package Ou t lin e Dim en sio ns (All Dimensions in mm)
Please see http://www.diodes.com/package-outlines.html for the latest version.
SO-8
1
b
e
E
A
A1
9° ( All sides)
4°±3°
c
Q
h
45°
R 0.1
7°
D
E0
E1
L
Seating Plane
Gauge Plane
SO-8
Dim
Min
Max
Typ
A
1.40
1.50
1.45
A1
0.10
0.20
0.15
b
0.30
0.50
0.40
c
0.15
0.25
0.20
D
4.85
4.95
4.90
E
5.90
6.10
6.00
E1
3.80
3.90
3.85
E0
3.85
3.95
3.90
e
--
--
1.27
h
-
--
0.35
L
0.62
0.82
0.72
Q
0.60
0.70
0.65
All Dimensions in mm
Suggested Pad Layout
Please see http://www.diodes.com/package-outlines.html for the latest version.
SO-8
CX
Y
Y1
X1
Dimensions
Value (in mm)
C
1.27
X
0.802
X1
4.612
Y
1.505
Y1
6.50
AP1509
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AP1509
IMPORTANT NOTICE
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE (AND THEI R EQUIVALENTS UNDER T HE LAWS OF ANY JURI S DICT ION).
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
arising out of the application or use of this document or any product descri bed herein; neither does Diodes Incorporated convey any license
under its patent or trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in suc h
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 Incorporated does not warrant or accept any liability whatsoever in res pect of any products purchased through unauthorized sales
channel.
Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall
indemnify and hold Di odes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney f ees arising
out of, directly or indirectl y, any cl aim of pers onal injury or deat h associat ed with such unintended or unauthorized application.
Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and
markings noted herein may also be covered by one or more United States, international or foreign trademarks.
This document is writt en in English but may be translat ed i nto multi ple languages for referenc e. Onl y the Englis h version of thi s document is
the final and determinat i ve format released by Diodes Incorporated.
LIFE SU PP O R T
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the
express written approval of t he Chief Executive Off i c er of Diodes Incorporated. 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 t o perform when properly used in accordance with instructions for us e provided in the
labeling can be reasonably expected to result in signifi cant injury to the user.
B. A critical component is any component in a life support device or syst em whose failure to perform can be reasonably expected to cause
the
failure of the life support device or to affect its safety or effectivenes s.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices 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, notwithstanding any
devices- or systems-related information or s upport that may be provided by Diodes I ncorporated. Further, Cust omers must fully indem nify
Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-
critical, l ife support devices or systems.
Copyright © 2018, Diodes Incorporated
www.diodes.com
AP1509
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