AOSMD AOZ1020-EVA Ezbuckâ ¢ 2a simple buck regulator evaluation board note Datasheet

AOZ1020-EVA
EZBuck™ 2A Simple Buck Regulator
Evaluation Board Note
General Description
Features
The AOZ1020 evaluation board is a fully assembled and
tested circuit board built with the AOZ1020 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 4.5V to 16V. The output voltage is
preset and can be adjusted from 0.8V to VIN–0.4V
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The AOZ1020-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 500kHz switching frequency. The current mode
control and integrated internal MOSFET minimize
component count, board area and total cost.
The AOZ1020 comes in SO-8 packages and is rated over
a -40°C to +85°C ambient temperature range.
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4.5V to 16V operating input voltage range
Output voltage is preset to 3.3V and adjustable down
to 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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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
C5
5V
C1
22µF Ceramic
R3
VIN
EN
PG
L1
4.7µH
AOZ1020
C6
VOUT
LX
COMP
RC
C4
AGND
PGND
R1
FB
CC
C2, C3
22µF Ceramic
R2
10kΩ
Figure 1.
Rev. 1.0 December 2007
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Page 1 of 4
AOZ1020-EVA
Component List
Ref
Designation
Value
Description
Manufacturer
Part Number
C1
22µF
Ceramic Cap, 22uF, 25V, 1210, X5R
GRM32ER61E226KE15L
C2
22µF
Ceramic Cap, 22uF, 25V, 1210, X5R
GRM32ER61E226KE15L
C3
22µF
Ceramic Cap, 22uF, 25V, 1210, X5R
GRM32ER61E226KE15L
C4
NU
C5
1µF
Ceramic Cap, 1uF, 25V, 0603, X5R
GRM188R61E105KA12D
Manufacturer
Murata
C6
1000pF
Ceramic Cap, 1000pF, 50V, 0603, X7R
GRM188R71E102K
Cc(2)
2200pF
Ceramic Cap, 2200pF, 50V, 0603, X7R
GRM188R71E222K
RC(2)
8.5kΩ
Thick Film Res, 1%, 31.6k, 0603
CRCW060385K5FKTAP
R1(1)
31.6kΩ
Thick Film Res, 1%, 31.6k, 0603
CRCW060331K6FKTAP
R2
10kΩ
Thick Film Res, 1%, 10k, 0603
CRCW060310K0FKTAP
R3
10kΩ
Thick Film Res, 1%, 10k, 0603
CRCW060310K0FKTAP
L1(2)
4.7µH
Inductor, 4.7uH, 2.9A
LQH55DN4R7M03
Murata
U1
AOZ1020AI
Buck regulator IC, 2A, 16V
AOZ1020AI
AOS
DALE
Notes:
1. For evaluation board with different output voltage, these values might be different.
8 + ( 10 × V O )
2. Output voltage is set by R1; R1 = ----------------------------------- . Table 1 shows that the value of R1 with typical output voltages.
0.8kΩ
Table 1.
Vo (V)
R1 (kΩ)
1.2
4.99
1.8
12.7
2.5
21.5
3.3
31.6
5.0
52.3
Rev. 1.0 December 2007
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Page 2 of 4
AOZ1020-EVA
PCB Layout
Figure 1. Top Silk Screen
Figure 2. Top Layer
Figure 3. Bottom Layer
Rev. 1.0 December 2007
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Page 3 of 4
AOZ1020-EVA
Quick Start Guide
1. Connect the terminals of load to +VOUT pins and GND pins. Set load current to between 0A and 2A.
2. Connect the DC power supply to +VIN pin and GND pins. Set DC power supply voltage to between 4.5V and 16V.
3. Connect EN pin to +VIN or any voltage source which is between 2V and 16V.
4. Turn on DC power supply and the evaluation circuit will start.
5. Measure input voltage at the +VIN pin and GND pins to eliminate the effect of voltage drop on wire between DC
power supply and 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 evaluation board.
7. Use an oscilloscope to monitor input ripple voltage right across input capacitor C1.
8. Use an oscilloscope to monitor output ripple voltage right across output capacitor C2.
This data sheet contains preliminary data; supplementary data may be published at a later date.
Alpha & Omega Semiconductor reserves the right to make changes at any time without notice.
LIFE SUPPORT POLICY
ALPHA & OMEGA SEMICONDUCTOR PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL
COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS.
As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant into
the body or (b) support or sustain life, and (c) whose
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of
the user.
Rev. 1.0 December 2007
2. A critical component in any component of a life
support, device, or system whose failure to perform can
be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or
effectiveness.
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