AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 1 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
Features General Description
AP5004 consists of step-down switching regulator with PWM
control. These devices include a reference voltage source,
oscillation circuit, error amplifier, internal NMOS.
• Input Voltage: 10V to 32V
• Adjustable Output Voltage from 0.8V to 6V
• Duty Ratio: 0% to 90% PWM control AP5004 provides low-ripple power, high efficiency and excellent
transient characteristics. The PWM control circuit is able to vary
the duty ratio linearly from 0 up to 90%. An enable function, an
over current protect function and a short circuit protect function are
built inside, and when OCP or SCP happens, the operation
frequency will be reduced from 300 KHz to 50 KHz. Also, an
internal compensation block is built to minimize external
component count.
• Oscillation Frequency: 300KHz typical
• Short Circuit Protect Frequency:50 KHz
• 2uA Maximum Standby Current
• Current Limit, Enable Function
• Thermal Shutdown Function
• Built-in Internal SW N-channel MOS
• SOP-8L: Available in “Green” Molding Compound
(No Br, Sb) With built-in power NMOS, a step-down switching regulator is
easy to be built by adding a coil, capacitors and a diode.
• Lead Free Finish/RoHS Compliant (Note 1)
The high efficiency, low standby current, high input voltage ( 32V)
and output current (2.5A) combining with small SOP-8L package
give AP5004 unprecedented advantage in high power system
applications.
• Microprocessor Core Supply
• Networking Power Supply
• LCD MNT, TV Power Supply
• Telecom Power Supply
Ordering Information
AP5004 S G - X
Package Packing
U : Tube
13 : Tape & Reel
Lead Free
G : Green
S : SOP-8L
Tube 13” Tape and Reel
Device Package
Code Packaging
(Note 2) Quantity Part Number
Suffix Quantity Part Number
Suffix
AP5004SG-U S SOP-8L 100 -U NA NA
AP5004SG-13 S SOP-8L NA NA 2500/Tape & Reel -13
Applications
Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied, see EU Directive 2002/95/EC Annex Notes.
2. Pad layout as shown on Diodes Inc. suggested d layout document AP02001, which can be found on our website at pa
http://www.diodes.com/datasheets/ap02001.pdf.
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 2 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
AP5004
1
2
37
6
54
8
(Top View )
GND
GND
Vcc
Vcc
EN
FB
Vboost
Output
SOP-8L
Pin
Name Pin # Description
EN 1
H: Normal operation
L: Step-down operation stopped
FB 2 Feedback pin
Vboost 3 High -side gate driver boo st pin
Output 4 Switch outp ut pin
VCC 5、6 Signal VCC
GND 7、8 GND pin
Block Diagram
Oscillation
Circuit Reference Volt age
PWM -Switched
Control Circuit +
-
GNDEN
Output
FB
Vboost
Vcc
VEN
Driver
Thermal
Shutdown
VL
Pin Assignments Pin Descriptions
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 3 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
Absolute Maximum Ratings
Symbol Parameter Rating Unit
ESD HBM Human Body Model ESD Protection 1.8 KV
ESD MM Machine Model ESD Protection 550 V
VCC VCC Pin Voltage VSS - 0.3 to VSS + 35 V
VFB VOUT Pin Voltage VSS - 0.3 to VCC V
VEN EN Pin Voltage VSS - 0.3 to VCC + 0.3 V
Vboost V
boost Pin Voltage VOUTPUT + 7V V
VOUTPUT Switch Pin Voltage VSS - 0.3 to VCC + 0.3 V
TJ Operating Junction Temperature Range -10 to +125 oC
TST Storage Temperature Ran ge -40 to +150 oC
Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be
exceeded under any conditions.
Recommended Operating Conditions
Symbol Parameter Min Max Unit
VIN Input Voltage 10 32 V
IOUT Output Current 0 2.5 A
TA Operating Ambient Temperature -10 85 oC
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 4 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
Electrical Characteristics (VIN = 12V, TA=25°C, unless otherwise specified)
Symbol Parameter Conditions Min Typ. Max Unit
VFB Feedback Voltage 0.780 0.8 0.820 V
VIN Input Voltage 10 - 32 V
ISTBY Standby Current VEN =0V - 2 - µA
∆VOUT/VOUT Line Regulation VIN = 10V~32V - ±1.0 ±1.5 %/V
∆VOUT/VOUT Load Regulation IOUT = 0.1 to 2.5A - 1 1.5 %
fOSC Oscillation Frequency Measure waveform at SW pin 240 300 360 KHz
fOSC1 Frequency of Current Limit or
Short Circuit Protect Measure waveform at SW pin - 50 - KHz
Maximum Duty Cycle VFB =0.5V - 90 - %
DC Minimum Duty Cycle VFB =1.0V - 0 - %
VIH Regulator ON 2.0 - -
VIL EN Pin Logic Input Threshold
Voltage Regulator OFF - - 0.8 V
ISH - 20 - µA
ISL EN Pin Input Leakage Current - -10 - µA
RDS(ON) Internal MOSFET RDS(ON) - 80 120 mΩ
ILIMIT Current Limit 3.5 - - A
η Efficiency VIN = 12V, VOUT = 5V, IOUT = 2.5A - 90 - %
θJA Thermal Resist ance
Junction-to-Ambient SOP-8L (Note 3) - 124 - oC/W
θJC Thermal Resi st ance
Junction-to-Case SOP-8L (Note 3) - 25 - oC/W
Notes: 3. Test condition for SOP-8L: Device mounted on 2oz copper, minimum recommended pad layout, FR-4 PCB.
Typical Application Circuit
Vboost
GND
VCC
AP5004
GND
VCC
Output
FB
EN
5
6
VIN
C3
0.1uF
1
C2
220uF/63V
8
34
2
7
D1
B340
R1
685ohm
L1-(WURTH 744132)
33uH
C5
0.1uF
C1
100pF
VOUT = 5V
R5
100K
C6
0.1uF
U1
C7 0.1uF
12
R2
130ohm
C4
470uF/16V
Note: V OUT = VFB x (1+R1/R2)
R B= 100 ~ 300 ohm
Notes: 4. Suggested DIODES Power Schottky P/N: PDS540 or B540C.
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 5 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
Typical Performance Characteristics
Line Regulation Load Regulation
0
0.2
0.4
0.6
0.8
1
1.2
0123
Iout(A)
Load Regulation(%)
0
0.3
0.6
0.9
1.2
1.5
0 4 8 121620242832
Vin(V)
Line Regu lation(%)
Frequency vs. Vin Iccq vs. Vin
310
315
320
325
330
0 5 10 15 20 25 30 35
Vin(V)
Frequency(KHz)
Vout=5V;Iout=0.2A
7.05
7.1
7.15
7.2
7.25
7.3
7.35
7.4
7.45
0 5 10 15 20 25 30 35
Vin(V)
Quiescen t Curren t(m A)
VFB=1V
Istandby vs. Vin
0
0.03
0.06
0.09
0.12
0.15
0 5 10 15 20 25 30 35
Vin(V)
Standby Current(uA)
VEN=0V
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 6 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
Typical Performance Characteristics (Continued)
Vout Ripple
(Vcc= 12V, Vout= 5V, Iout= 0A, Vripple= 19.0mV) Vout Ripple
(Vcc= 12V, Vout= 5V, Iout= 2.5A, Vripple= 35.0mV)
Power Transient Wav e
(Iout= 0.1~2.5A, Vin= 12V, Vout= 5V) Power Transient Wave
(Iout= 0.1~2.5A, Vin= 32V, Vout= 5V)
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 7 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
Test Circuit
A
FBVcc
GND
EN
open
open
FB
Vcc
GND
EN
+
-
Oscillation
OUTPUT OUTPUT
A
FB
Vcc
GND
EN
+
-+
-
V
OUTPUT
Vboost open
Vboost
Vboost
Enable function test Feedback function test
Operation function test
220uF
0.1uF
33uH
470uF
530 ohm
100 ohm
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 8 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
Functional Description
PWM Control
The AP5004 consists of DC/DC converters that employ a
pulse-width modulation (PWM) system. The PWM controller is
internally clocked by a fixed 300KHz oscillator.
In converters of the AP5004, the pulse width varies in a range
from 0 to 90%, according to the load current. The ripple voltage
produced by the switching can easily be removed through a filter
because the switching frequency remains constant. Therefore,
these converters provide a low-ripple power over broad ranges of
input voltage and load current.
Enable Control
This allows the output of AP5004 to be turned ON or OFF.
Connecting this pin to GND or any voltage lower than 0.8V turn
off the output OFF. At OFF state current drawn through the VCC
input is approximately 2uA. Note that the slew rate from ON to
OFF must be >0.013v/us to ensure proper operation.
C BOOST
A capacitor must be connected from pin 3 to the switch output,
pin 4. This capacitor boosts the gate drive to the internal
MOSFET above VIN to fully turn it ON. This minimizes conduction
losses in the power switch to maintain high efficiency. The
recommended value for C Boost is 0.1uF.
FEEDBACK
This is the input to a two-stage high gain amplifier, which drivers
the PWM controller. It is necessary to connect pin 2 to the actual
output of the power supply to set the DC output voltage. Two
external resistors are required to set the DC output voltage. For
stable operation of the power supply, it is important to prevent
coupling of any inductor flux to the feedback input.
Current Limit
The current limit threshold is set by the internal circuit that
minimum switching current is 3.5A. The output voltage will be
reduced immediately and switching frequenc y will be dropped to
50KHz when switching current over limit threshold.
Inductor Selection
For most designs, the operates with inductors of 15µH to 33µH.
The inductor value can be derived from the following equation:
()
oscL
ONOUTIN fI TVV
L×Δ
−
=
Where is inductor Ripple Current. Large value inductors lower
ripple current and small value inductors result in high ripple
currents. Choose inductor ripple current approximately 15% of
the maximum load current 2.5A, ∆IL=0.375A. The DC current
rating of the inductor should be at least equal to the maximum
load current plus half the ripple current to p revent c ore satu ration
(2A+0.19A).
Input Capacitor Selection
The input current to the step-down converter is discontinuous,
and therefore an input capacitor C2 is required to supply the AC
current to the step-down converter while maintaining the DC input
voltage. A low ESR capacitor is required to keep the noise at the
IC to a minimum. Its RMS current rating should be greater than
approximately 1/2 of the DC load current.
Output Capacitor Selection
The output capacitor is required to maintain the DC output
voltage. Low ESR capacitors are preferred to keep the output
voltage ripple low. The characteristics of the output capacitor also
affect the stability of the regulation control system. The
ESR dominates the impedance at the switching frequency, and
so the output ripple is calculated as:
ESRRIPPLE RIV ×Δ≅
Output Rectifier Diode
The output rectifier diode supplies the current to the inductor
when the high-side switch is off. To reduce losses due to the
diode forward voltage and recovery times, use a Schottky
rectifier.
PCB Layout Guide
If you need low TC & TJ or large PD(Power Dissipation), The dual
Output pin(4) and VSS pins(7& 8)on the SOP-8L package are
internally connected to die pad, The PCB layout should allow for
maximum possible copper area at the SW pins.
1. Connect C3 to VCC and VSS pin as closely as possible to get
good power filter effect.
2. Connect ground side of the C2 & D1 as closely as possible.
Typical PC Board Layout
Top Side Layout Guide
Bottom Side Layout Guide
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 9 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
Marking Information
( Top View )
SOP-8L
AP5004
YY WW
XX
Logo
Part No. Internal code
Year : "07" = 2007
"08" = 2008
Xth week : 01~52
~
5
8
41
A~Z : Green
Package Information (All Dimensions in mm)
1.27typ 0.3/0.5
7°~9°
4.80/5.30
3.70/4.10
5.79/6.20
0.20typ
7°~9°
3.70/4.10
0.38/1.27
0.08/0.25
Gauge Plane
0.254
Seating Plane
0.35max. 45°
Detail "A"
Detail "A"
1.30/1.50
1.75max.
Land Pattern Recommendation
0.78
(Unit: mm)
6x-1.27
8x-1.55
8x-0.60
5.4
AP5004
PWM CONTROL 2.5A STEP-DOWN CONVERTER
AP5004 Rev. 3 10 of 10 JUNE 2008
www.diodes.com © Diodes Incorporated
IMPORT ANT NOTICE
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notice to any product herein. Diodes Incorporated does not assume any liability arising out of the application or use of any product described herein; neither
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Diodes Incorporated products are not authorized for use as critical components in life support devices or systems without the expressed written approval of the
President of Diodes Incorporated.
