DIODES AP5002SG-13

AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
General Description
Features
•
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Input voltage: 3.6V to 20V
Output voltage: 0.8V to VCC
Duty ratio: up to 100% PWM control
Oscillation frequency: 500KHz typical
Soft-start Current Limit, Enable function
Thermal Shutdown function
Built-in internal SW P-channel MOS
Low ESR output capacitor (MLCC, multi-layer ceramic
capacitor) support
Efficiency 90%
SOP-8L: Available in “Green” Molding Compound
(No Br, Sb)
Lead Free Finish / RoHS Compliant (Note 1)
AP5002 consists of step-down switching regulator with PWM
control. These devices include a reference voltage source,
oscillation circuit, error amplifier, internal PMOS.
AP5002 provides low-ripple power, high efficiency, and excellent
transient characteristics. The PWM control circuit is able to vary
the duty ratio linearly up to 100%. This converter also contains
an error amplifier circuit as well as a soft-start circuit that prevents
overshoot at startup. 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 500KHz to 50KHz. Also, an internal compensation
block is built in to minimum external component count.
With the addition of an internal P-channel Power MOS, a coil,
capacitors, and a diode connected externally, these ICs can
function as step-down switching regulators. They serve as ideal
power supply units for portable devices when coupled with the
SOP–8L mini-package, providing such outstanding features as
low current consumption. Since this converter can accommodate
an input voltage up to 22V, it is also suitable for the operation via
an AC adapter.
Applications
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PC Motherboard
LCD Monitor
Graphic Card
DVD-Video Player
Telecom Equipment
ADSL Modem
Printer and other Peripheral Equipment
Microprocessor core supply
Networking power supply
Ordering Information
AP5002 S G - X
Package
S : SOP-8L
Device
Package
Code
Packaging
(Note 2)
AP5002SG-U
AP5002SG-13
S
S
SOP-8L
SOP-8L
Notes:
Lead Free
G : Green
Packing
U : Tube
13 : Taping & Reel
Tube
Part Number
Quantity
Suffix
100
-U
NA
NA
13” Tape and Reel
Part Number
Quantity
Suffix
NA
NA
2500/Tape & Reel
-13
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 pad layout document AP02001, which can be found on our website at
http://www.diodes.com/datasheets/ap02001.pdf.
AP5002 Rev. 6
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© Diodes Incorporated
AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Pin Assignments
Pin Descriptions
( Top View )
8
Vss
7
Vss
Comp 3
6
Output
VCC 4
5
Output
FB 1
EN 2
Name Pin
FB
1
EN
AP5002
Comp
VCC
Output
SOP-8L
VSS
Description
Feedback pin
Power-off pin
H: Normal operation
2
(Step-down operation)
L: Step-down operation stopped
(All circuits deactivated)
3
Compensation pin
4
IC power supply pin
Switch Pin. Connect external
5、6 inductor/diode here. Minimize trace
area at this pin to reduce EMI.
7、8 GND Pin
Block Diagram
Output
Oscillation
Circuit
Reference Voltage Source
Vcc
+
PWM-Switched
Control Circuit
FB
-
Thermal
Shutdown
100uA
VEN
EN
AP5002 Rev. 6
2 of 10
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Vss
Comp
JUNE 2008
© Diodes Incorporated
AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Absolute Maximum Ratings
Symbol
Parameter
ESD HBM Human Body Model ESD Protection
ESD MM
VCC
VFB
VEN
VOUTPUT
PD
TJ
TST
Machine Model ESD Protection
VCC Pin Voltage
Feedback Pin Voltage
EN Pin Voltage
Switch Pin Voltage
Power Dissipation
Operating Junction Temperature Range
Storage Temperature Range
Rating
Unit
5
200
VSS - 0.3 to VSS + 22
VSS - 0.3 to VCC
VSS - 0.3 to VIN
VSS - 0.3 to VIN
1000
-20 to +125
-65 to +150
KV
V
V
V
V
V
mW
o
C
o
C
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
VIN
IOUT
TA
AP5002 Rev. 6
Parameter
Input Voltage
Output Current
Operating Ambient Temperature
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Min
3.6
0
-20
Max
20
2
85
Unit
V
A
o
C
JUNE 2008
© Diodes Incorporated
AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Electrical Characteristics
Symbol
VFB
IFB
ICCQ
ISW
ISD
∆VOUT
/VOUT
∆VOUT
/VOUT
fOSC
VSH
VSL
ISH
ISL
TSS
RDSON
θJA
θJC
Notes:
(VIN = 12V, TA = 25°C, unless otherwise specified)
Parameter
Feedback Voltage
Feedback Bias Current
Quiescent Current
Switch Current
Shutdown Supply Current
Min
0.784
3.5
-
Typ.
0.8
0.1
3
10
Max
0.816
0.5
5
-
Unit
V
µA
mA
A
µA
IOUT = 0.1A
IOUT = 0.1A
VFB = 1.2 force drive off
-VEN = 0V
Line Regulation
VIN = 4V~20V, IOUT = 0.2A
-
1
2
%
Load Regulation
IOUT = 0.1 to 2A
-
0.5
1
%
Oscillation Frequency
Measure waveform at SW pin
Evaluate oscillation at SW pin
Evaluate oscillation stop at SW pin
Ven = 2V
Ven = 0.8V
-VIN = 5V, VFB = 0V
VIN = 12V, VFB = 0V
400
2.0
-10
-10
-
500
3
110
70
600
0.8
10
10
150
100
KHz
EN Pin Input Voltage
EN Pin Input Leakage
Current
Soft-Start Time
Internal MOSFET Rdson
Conditions
V
µA
µA
ms
mΩ
Thermal shutdown
140
o
Minimum Duty Cycle
6.5
%
Thermal Resistance
Junction-to-Ambient
Thermal Resistance
Junction-to-Case
C
SOP-8L (Note 3)
124
o
SOP-8L (Note 3)
25
o
C/W
C/W
3. Test condition: Device mounted on 2oz copper, minimum recommended pad layout, FR-4 PCB.
AP5002 Rev. 6
4 of 10
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JUNE 2008
© Diodes Incorporated
AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Typical Application Circuit
U1
VIN+12V
1
C2
22uF
C3
ON/OFF
R5
100K
2
3
0.1uF
C6
0.1uF
4
FB
VSS
EN
VSS
COMP
Output
VCC
Output
8
7
L1-(WURTH S05100104)
10uH
2
1
6
D1
Dii 723
B340A
5
R1
3.8K
VOUT = 3.3V
C1
330pF
C8
0.1uF
AP5002
R4
0.8~2K
C4
22uF
R2
1.2K
C7
0.1uF
Compensation Capacitor Selection(MLCC)
VIN
VOUT
R4
C7
C1
12V
5/ 3.3/ 2.5/ 1.8/ 1.5V
0.8~2K
0.1µF
330pF
5V
3.3/ 2.5/ 1.8/ 1.5V
0.8~2K
27nF
330pF
VIN+12V
U1
C2
470uF
C3
0.1uF
R5
100K
1
FB
VSS
2
EN
VSS
ON/OFF
C6
0.1uF
3
COMP
Output
4
VCC
Output
4.
VOUT = VFB × (1+
AP5002 Rev. 6
R1
R2
L1-(WURTH S05100104)
10uH
7
6
5
AP5002
R4
4.7~6.8K
Notes:
8
C7
33nF
1
D1
Dii 723
B340A
VOUT = 3.3V
2
R1
3.8K
C1
330pF
C8
0.1uF
C4
470uF
R2
1.2K
)
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AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Typical Performance Characteristics
570
575
560
Frequency(KHZ)
Frequency(KHZ)
AP5002 Temperature vs. Frequency
(Vout=3.3V; Iout=0.2A)
AP5002 Vin vs. Frequency
(Vout=3.3V; Iout=0.2A)
550
540
530
545
530
515
500
520
485
510
0
5
10 Vin(V) 15
20
-20
25
0
20
40
60
Temperature( ℃)
80
100
120
AP5002 Temperature vs. FB
(Vout=3.3V; Iout=0.2A)
AP5002 Vin vs. FB
(Vout=3.3V; Iout=0.2A)
0.808
0.82
0.806
0.81
VFB(V)
VFB(V)
560
0.804
0.802
0.8
0.79
0.8
0.78
0
5
10
15
Vin(V)
20
25
-20
30
80
Temperature( ℃)
130
AP5002 Efficiency
100
90
Vout=5V
Efficiency(%)
80
70
Vout=3.3V
60
50
40
30
20
10
0
0
AP5002 Rev. 6
0.5
1
Iout(A)
1.5
2
6 of 10
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AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Typical Performance Characteristics
(Continued)
AP5002 Line Regulation
3.35
3.34
3.34
3.33
3.33
Vout(V)
Vout(V)
AP5002 Load Regulation
3.35
3.32
3.31
3.32
3.31
3.3
0
0.5
1
Iout(A)
1.5
3.3
2
0
5
ICCQ(mA)
ICCQ(mA)
4
3
2
1
-20
AP5002 Rev. 6
10
Vin(V)
15
Vin(V)
15
20
25
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
0
5
10
AP5002 Temperature vs. I CCQ
(Vout=3.3V)
AP5002 Vin vs. I CCQ (Vout=3.3V)
0
5
20
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0
20
40
60
Temperature( ℃)
80
100
120
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AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Typical Performance Characteristics
(Continued)
AP5002 Vout Ripple
(Vin=12V; Vout=5V; Iout=2A)
AP5002 Vout Ripple
(Vin=12V; Vout=5V; Iout=0.2A)
Test Circuit
VCC
OUTPUT
FB
Oscillation
open
open
COMP
A
EN
+
-
VSS
Enable function test
VCC
OUTPUT
OUTPUT
COMP
EN
FB
VSS
FB
COMP
EN
VCC
Feedback function test
22u
6.8K
6.8K 1500p
+
-
A
+
VSS
-
V
1.2K
Operation function test
AP5002 Rev. 6
8 of 10
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AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Functional Description
PWM Control
The AP5002 consists of DC/DC converters that employ a
pulse-width modulation (PWM) system.
In converters of the AP5002, the pulse width varies in a range up
to 100%, 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.
RDS(ON) Current Limiting
The current limit threshold is set by the internal circuit.
Setting the Output Voltage
Application circuit item shows the basic application circuit with
adjustable output version. The external resistor sets the output
voltage according to the following equation:
VOUT (V)
5
3.3
2.5
1.8
1.5
1.2
1
R1 (KΩ)
6.4
3.8
2.6
3.3
3.3
3.3
3.3
R2 (KΩ)
1.2
1.2
1.2
2.6
3.7
6.5
13
Inductor Selection
For most designs, the operates with inductors of 10µH to
22µH. The inductor value can be derived from the following
equation:
L=
value. For the output capacitor, the ESR value is the most
important parameter. The output ripple can be calculated from
the following formula.
VRIPPLE = ΔIL × ESR
The bulk capacitor’s ESR will determine the output ripple voltage
and the initial voltage drop after a high slew-rate transient.
An aluminum electrolytic capacitor's ESR value is related to the
capacitance and its voltage rating. In most case, higher voltage
electrolytic capacitors have lower ESR values. Most of the time,
capacitors with much higher voltage ratings may be needed to
provide the low ESR values required for low output ripple voltage.
MLCC CAP
A 22µF MLCC capacitor for most applications is sufficient.
PCB Layout Guide
If you need low TC & TJ or large PD(Power Dissipation), The dual
SW pins(5& 6) 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 R4 to VCC and OCSET pin as closely as possible.
3. Connect ground side of the C2 & D1 as closely as possible.
Typical PC Board Layout
Top Side Layout Guide
(VIN
− VOUT )TON
2 × ΔI L × f osc
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 2A, ∆IL=0.3A. The DC current rating of the
inductor should be at least equal to the maximum load current
plus half the ripple current to prevent core saturation (2A+0.15A).
Input Capacitor Selection
EL CAP
This capacitor should be located close to the IC using short leads
and the voltage rating should be approximately 1.5 times the
maximum input voltage. The RMS current rating requirement for
the input capacitor of a buck regulator is approximately 1⁄2 the
DC load current. A low ESR input capacitor sized for maximum
RMS current must be used. A 470µF low ESR capacitor for most
applications is sufficient.
Use vias to conduct the heat into the backside of
PCB layer. The PCB heat sink copper area should be
solder-painted without masked. This approaches a
Bottom Side Layout Guide
MLCC CAP
A 22µF MLCC capacitor for most applications is sufficient.
Output Capacitor Selection
EL CAP
The output capacitor is required to filter the output voltage and
provides regulator loop stability. The important capacitor
parameters are the 100KHz Equivalent Series Resistance (ESR),
the RMS ripples current rating, voltage rating and capacitance
AP5002 Rev. 6
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AP5002
PWM CONTROL 2A STEP-DOWN CONVERTER
Marking Information
(Top view)
8
7
6
5
Logo
AP5002
Part Number
G : Green
YY XX X
2
1
X
3
Internal Code
Xth week: 01~52
Year: "07" = 2007
"08" = 2008
4
~
SOP-8L
0.254
0.08/0.25
5.79/6.20
(All Dimensions in mm)
3.70/4.10
Package Information
Gauge Plane
Seating Plane
0.38/1.27
Detail "A"
7°~9°
7°~9°
0.20typ
1.30/1.50
0.3/0.5
1.27typ
1.75max.
0.35max. 45°
Detail "A"
0.78
3.70/4.10
4.80/5.30
5.4
8x-0.60
8x-1.55
6x-1.27
Land Pattern Recommendation
(Unit: mm)
IMPORTANT NOTICE
Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further
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
does it convey any license under its patent rights, nor the rights of others. The user of products 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 our website, harmless against all damages.
LIFE SUPPORT
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.
AP5002 Rev. 6
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