Evalboard Notes

AOZ1018-EVA
EZBuck™ 2A Simple Buck Regulator
Evaluation Board Note
General Description
Features
The AOZ1018 evaluation board is a fully assembled and
tested circuit board built with the AOZ1018 buck regulator
IC. It outputs a preset or adjustable voltage at up to 2A of
continuous current. The evaluation board requires an
input voltage from 4.5 V to 16 V. The output voltage is
preset and can be adjusted from 0.8 V to VIN–0.4V
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The AOZ1018-EVA circuit has features like current limit,
short circuit protection, input under voltage lock out,
internal soft start and thermal shut down. It operates at
a fixed 500 kHz switching frequency. The current mode
control and integrated internal MOSFET minimize
component count, board area and total cost.
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4.5V to 16V operating input voltage range
Output voltage was preset to 3.3 V, adjustable to as
low as 0.8V
2A continuous output current
Fixed 500kHz PWM operation
Internal soft start
Cycle-by-cycle current limit
Short-circuit protection
Thermal shutdown
Applications
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The AOZ1018 comes in SO-8 package and is rated over
a -40°C to +85°C ambient temperature range.
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Point of load DC/DC conversion
PCIe graphics cards
Set top boxes
DVD drives and HDD
LCD panels
Cable modems
Telecom/networking/datacom equipment
Evaluation Board Schematic
VIN
C1
22µF
Ceramic
C7
1µF
VIN
From µPC
L1 3.3µH
U1
EN
AOZ1018
C2
C3
COMP
R1
C5
Rev. 1.1 January 2007
VOUT
LX
R2
FB
AGND
PGND
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D1
+3.3V Output
@2A
C4, C6
22µF Ceramic
R3
Page 1 of 6
AOZ1013-EVA
Component List
Ref
Designation
Value
Description
Manufacture Part Number
Manufacture
Murata
C1
22µF
Ceramic Cap, 22uF, 25V, 1210, X5R
GRM32ER61E226KE15L
C2
1000pF
Ceramic Cap, 1000pF, 50V, 0603, X7R
GRM188R71E102K
C3
NU
C4
22µF
Ceramic Cap, 22uF, 25V, 1210, X5R
GRM32ER61E226KE15L
C5*
1000pF
Ceramic Cap, 1000pF, 50V, 0603, X7R
GRM188R71E102K
C6
22µF
Ceramic Cap, 22uF, 25V, 1210, X5R
GRM32ER61E226KE15L
C7
1µF
Ceramic Cap, 1uF, 25V, 0603, X5R
GRM188R61E105KA12D
R1*
31.6kΩ
Thick Film Res, 1%, 31.6k, 0603
CRCW060331K6FKTAP
R2*
31.6kΩ
Thick Film Res, 1%, 31.6k, 0603
CRCW060331K6FKTAP
R3
10kΩ
Thick Film Res, 1%, 10k, 0603
CRCW060310K0FKTAP
L1*
3.3µH
Inductor, 3.3uH, 2.9A
LQH55DN3R3M03
Murata
Schottky Barrier Diode, 2A, 30V, SMA
B230A-FDICT-ND
DIODES
Buck regulator IC, 2A, 16V
AOZ1018AI
AOS
D1
U1
AOZ1018AI
DALE
*For evaluation board with different output voltage, these values might be different.
Ordering Information
Part Number
Output Preset Voltage
IC package
Ambient Temperature Range
AOZ1018-EVA-8.0V
8V
SO-8
-40°C to +85°C
AOZ1018-EVA-5.0V
5.0 V
SO-8
-40°C to +85°C
AOZ1018-EVA-3.3V
3.3 V
SO-8
-40°C to +85°C
AOZ1018-EVA-2.5V
2.5 V
SO-8
-40°C to +85°C
AOZ1018-EVA-1.8V
1.8 V
SO-8
-40°C to +85°C
Rev. 1.1 January 2007
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Page 2 of 6
AOZ1013-EVA
PCB Layout (1" x 1.25")
Figure 1. Top Silk Screen
Figure 2. Top Layer
Figure 3. Bottom Layer
Rev. 1.1 January 2007
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Page 3 of 6
AOZ1013-EVA
BOM of 8V/2A AOZ1018 Regulator
Ref Designation
Value
C1
22µF
C2
1000pF
C3
NU
C4
22µF
Ceramic Cap, 25V, X7R/X5R
1210
C5
820pF
Ceramic Cap, 50V, X7R
0603
C6
22µF
Ceramic Cap, 25V, X7R/X5R
1210
C7
1µF
Ceramic Cap, 25V, X5R
0603
R1
80.6kΩ
Thick Film Res, 1%
0603
R2
90.9kΩ
Thick Film Res, 1%
0603
R3
10kΩ
Thick Film Res, 1%
0603
L1
10µH
Inductor LQH55 series
D1
U1
Description
Ceramic Cap, 25V, X7R/X7R
Ceramic Cap, 50V, X7R
1210
Manufactures
Murata, AVX
0603
0603
Schottky Barrier Diode, 2A, 30V, SMA
AOZ1018A
Package
Buck regulator IC
DALE
Murata
B230A-FDICT-ND
SO-8
DIODES
AOS
BOM of 5V/2A AOZ1018 Regulator
Ref Designation
Value
C1
22µF
C2
1000pF
C3
NU
C4
22µF
C5
1000pF
C6
C7
Description
Package
Ceramic Cap, 25V, X7R/X5R
1210
Ceramic Cap, 50V, X7R
0603
1210
Ceramic Cap, 50V, X7R
0603
22µF
Ceramic Cap, 25V, X7R/X5R
1210
1µF
Ceramic Cap, 25V, X5R
0603
R1
49.9kΩ
Thick Film Res, 1%
0603
R2
52.3kΩ
Thick Film Res, 1%
0603
R3
10kΩ
Thick Film Res, 1%
0603
L1
4.7µH
Inductor LQH55 series
U1
Rev. 1.1 January 2007
Schottky Barrier Diode, 2A, 30V, SMA
AOZ1018A
Murata, AVX
0603
Ceramic Cap, 25V, X7R/X5R
D1
Manufactures
Buck regulator IC
www.aosmd.com
DALE
Murata
B230A-FDICT-ND
SO-8
DIODES
AOS
Page 4 of 6
AOZ1013-EVA
BOM of 3.3V/2A AOZ1018 Regulator
Ref Designation
Value
C1
22µF
C2
1000pF
C3
NU
C4
22µF
C5
1000pF
C6
22µF
Ceramic Cap, 25V, X7R/X5R
1210
C7
1µF
Ceramic Cap, 25V, X5R
0603
R1
31.6kΩ
Thick Film Res, 1%
0603
R2
31.6kΩ
Thick Film Res, 1%
0603
R3
10kΩ
Thick Film Res, 1%
0603
L1
3.3µH
Inductor LQH55 series
D1
U1
Description
Ceramic Cap, 25V, X7R/X5R
Ceramic Cap, 50V, X7R
1210
Manufactures
Murata, AVX
0603
0603
Ceramic Cap, 25V, X7R/X5R
1210
Ceramic Cap, 50V, X7R
0603
Schottky Barrier Diode, 2A, 30V, SMA
AOZ1018A
Package
Buck regulator IC
DALE
Murata
B230A-FDICT-ND
SO-8
DIODES
AOS
BOM of 1.8V/2A AOZ1018 Regulator
Ref Designation
Value
C1
22µF
C2
1000pF
C3
NU
C4
22µF
C5
1500pF
C6
C7
Description
Package
Ceramic Cap, 25V, X7R/X5R
1210
Ceramic Cap, 50V, X7R
0603
1210
Ceramic Cap, 50V, X7R
0603
22µF
Ceramic Cap, 25V, X7R/X5R
1210
1µF
Ceramic Cap, 25V, X5R
0603
R1
20kΩ
Thick Film Res, 1%
0603
R2
12.4kΩ
Thick Film Res, 1%
0603
R3
10kΩ
Thick Film Res, 1%
0603
L1
2.2µH
Inductor LQH55 series
U1
Rev. 1.1 January 2007
Schottky Barrier Diode, 2A, 30V, SMA
AOZ1018A
Murata, AVX
0603
Ceramic Cap, 25V, X7R/X5R
D1
Manufactures
Buck regulator IC
www.aosmd.com
DALE
Murata
B230A-FDICT-ND
SO-8
DIODES
AOS
Page 5 of 6
AOZ1013-EVA
Quick Start Guide
1.
2.
3.
4.
5.
Connect the terminals of load to +VOUT pins and GND pins. Set load current between 0A and 2A.
Connect the DC power supply to +VIN pin and GND pins. Set DC power supply voltage between 4.5V and 16V.
Connect EN pin to +VIN or any voltage source which is between 2.0V and 16V.
Turn on DC power supply and evaluation circuit will start.
Measure input voltage at the +VIN pin and GND pins to eliminate the effect of voltage drop on wire between DC
power supply and the evaluation board.
6. Measure output voltage at the +VOUT pin and GND pins to eliminate the effect of voltage drop on wire between load
and the evaluation board.
7. Use an oscilloscope to monitor input ripple voltage across input capacitor C1.
8. Use an oscilloscope to monitor output ripple voltage across output capacitor C4.
Rev. 1.1 January 2007
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Page 6 of 6