Diodes AP1507 User Manual
Description
The AP1507 is a monolithic IC designed for a step-down DC/DC
converter and is capable of driving a 3A load without an external
transistor. Due to reducing the number of external components, 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 the feedback control have good
line and load regulation without an external design. Regarding the
protected function, the thermal shutdown is to prevent over
temperature operating from damaging the device, and current limit is
against over current operating of the output switch. If the current limit
function occurred and V
frequency will be reduced. The AP1507 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 +
tolerance on output voltage under specified input voltage and output
load conditions, and +
version included a fixed 3.3V, 5V, 12V, and an adjustable type.
AP1507 is available in a 5-lead TO-252 lead-free or green package.
Features
is down to 0.5V below, the switching
FB
4%
15% on the oscillator frequency. The output
AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
Pin Assignments
(Top View)
5 SD
4 FB
3 GND
2 Output
1 V
IN
Metal Tab GND
TO252-5L
Applications
• Output Voltage: 3.3V, 5V, 12V and Adjustable Output Version
• Adjustable Version Output Voltage Range, 1.23V to 18V +
• 150KHz +
• Voltage Mode Non-Synchronous PWM Control
• Thermal-Shutdown and Current-Limit Protection
• ON/OFF Shutdown Control Input
• Operating Voltage can be up to 22V
• Output Load Current: 3A
• Low Power Standby Mode
• Built-in Switching Transistor On Chip
• AP1507-XXD5L-XX
Totally Lead-Free; RoHS Compliant (Notes 1 & 2)
• AP1507-XXD5-XX
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 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.
15% Fixed Switching Frequency
4%
• Simple High-Efficiency Step-Down Regulator
• On-Card Switching Regulators
• Positive to Negative Converter
AP1507
Document number: DS31067 Rev. 3 - 2
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May 2012
© Diodes Incorporated
×
Typical Application Circuit
(1) Fixed Type Circuit
AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
12V
DC Input
C
in
Capacitor
(2) Adjustable Type Circuit
12V
DC Input
C
in
Capacitor
FB
4
AP1507
12
V
in
-33
SD
Output
35
GND
R2
FB
4
12
V
in
AP1507
Output
35
SD
GND
L1
33uH
Inductor
D1
Schottky
Diode
R1
L1
47uH
D1
Schottky Diode
3.3V/3A
Output Load
Co
Capacitor
5V/ 3A
Output Load
Co
Capacitor
V
= V
OUT
FB
(1 +
R1
)
R2
V
= 1.23V, R2 = 1K ~ 3K
FB
(3) Delay Start Circuit
R2
FB
12V
4
DC Input
12
AP1507
in
35
SD
R
DELAY
C
in
Capacitor
C
DELAY
0.1uF
V
10K
AP1507
Document number: DS31067 Rev. 3 - 2
www.diodes.com
GND
Output
2 of 12
R1
L1
47uH
D1
Schottky Diode
5V/ 3A
Output Load
Co
Capacitor
May 2012
© Diodes Incorporated
Pin Descriptions
Pin Number Pin Name Description
V
1
2 Output Switching Output
3 GND Ground
4 FB Output Voltage Feedback Control
5 SD
Functional Block Diagram
IN
Operating Voltage Input
ON / OFF Shutdown
AP1507
150KHz, 3A PWM BUCK DC/DC CONVERTER
SD
FB
Current
Source
Bias
1.235V
Reference
+
_
Amp
2.5V
Regulator
Frequency
Compen-
sation
_
Comp
+
Start
Up
150kHz
OSC.
Comp
Comp
Pre-
Driver
Thermal
Shutdown
200mV
+
_
_
+
220mV
3A
Switch
V
IN
Output
GND
AP1507
Document number: DS31067 Rev. 3 - 2
3 of 12
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May 2012
© Diodes Incorporated
AP1507
Absolute Maximum Ratings (T
Symbol Parameter Rating Unit
ESD HBM Human Body Model ESD Protection 2 KV
ESD MM Machine Model ESD Protection 200 V
VCC
VSD
VFB
V
OUT
PD
TST
TJ
Note: 4. Stresses greater than the 'Absolute Maximum Ratings' specified above, may cause permanent damage to the device. These are stress ratings
only; functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device
reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time.
Supply Voltage +24 V
ON/OFF Pin Input Voltage -0.3 to +18 V
Feedback Pin Voltage -0.3 to +18 V
Output Voltage to Ground -1 V
Power Dissipation Internally Limited W
Storage Temperature -65 to +150
Operating Junction Temperature -40 to +125
Recommended Operating Conditions (T
Symbol Parameter Min Max Unit
I
OUT
VOP
TA
Output Current 0 3 A
Operating Voltage 4.5 22 V
Operating Ambient Temperature -20 +85
= 25°C) (Note4)
A
150KHz, 3A PWM BUCK DC/DC CONVERTER
o
C
o
C
= 25°C)
A
o
C
AP1507
Document number: DS31067 Rev. 3 - 2
4 of 12
www.diodes.com
May 2012
© Diodes Incorporated
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