Rev. 1.0 October 2007
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Page 1 of 4
AOZ1019-EVA
EZBuck™ 2A Simple Buck Regulator
Evaluation Board Note
General Description
The AOZ1019 evaluation board is a fully assembled and
tested circuit board built with the AOZ1019 buck regulator
IC. It outputs a preset or adjustable voltage and 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 V
IN
–0.4V
The AOZ1019-EVA circuit features include; 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 AOZ1019 comes in an SO-8 package and is rated
over a -40°C to +85°C ambient temperature range.
Features
●
4.5V to 16V operating input voltage range
●
Output voltage was preset to 3.3V, 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
●
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
Figure 1.
LX
VIN
VOUT
+3.3V Output
@2A
VIN
From µPC
FB
PGND
EN
COMP
AGND
C2, C3
22µF
Ceramic
R1
R2
RC
CCD1
C5
C4
L1 4.7µH
AOZ1019
C1
22µF
Ceramic
C6
1µF
AOZ1019-EVA
Rev. 1.0 October 2007
www.aosmd.com
Page 2 of 4
Component List
Note:
1. Output voltage is set by R1; R1 = . Table 1 shows that the value of R1 with typical output voltages.
Table 1.
Ref
Designation Value Description
Manufacturer
Part Number Manufacturer
C1 22µF Ceramic Cap, 22µF, 25V, 1210, X5R GRM32ER61E226KE15L Murata
C2 22µF Ceramic Cap, 22µF, 25V, 1210, X5R GRM32ER61E226KE15L
C3 22µF Ceramic Cap, 22µF, 25V, 1210, X5R GRM32ER61E226KE15L
C4 NU
C5 1000pF Ceramic Cap, 1000pF, 50V, 0603, X7R GRM188R71E102K
C6 1µF Ceramic Cap, 1µF, 25V, 0603, X5R GRM188R61E105KA12D
C
C
1000pF Ceramic Cap, 1000pF, 50V, 0603, X7R GRM188R71E102K
R1
(1)
31.6k
Ω
Thick Film Res, 1%, 31.6k, 0603 CRCW060331K6FKTAP DALE
R2 20k
Ω
Thick Film Res, 1%, 20k, 0603 CRCW060321K0FKTAP
R
C
20k
Ω
Thick Film Res, 1%, 20k, 0603 CRCW060321K0FKTAP
L1 4.7µH Inductor, 4.7µH, 2.9A LQH55DN3R3M03 Murata
D1 Schottky Barrier Diode, 2A, 30V, SMA B230A-FDICT-ND DIODES
U1 AOZ1019AI Buck Regulator IC, 2A, 16V AOZ1019AI AOS
V
O
(V) R1 (k
Ω
)
1.2 4.99
1.8 12.7
2.5 21.5
3.3 31.6
5.0 52.3
810V
O
×()+
0.8kΩ
-----------------------------------
AOZ1019-EVA
Rev. 1.0 October 2007
www.aosmd.com
Page 3 of 4
PCB Layout
Figure 1. Top Silk Screen
Figure 2. Top Layer
Figure 3. Bottom Layer
AOZ1019-EVA
Rev. 1.0 October 2007
www.aosmd.com
Page 4 of 4
Quick Start Guide
1. Connect the terminals of load to +V
OUT
pins and GND pins. Set load current to between 0A and 2A.
2. Connect the DC power supply to +V
IN
pin and GND pins. Set DC power supply voltage to between 4.5V and 16V.
3. Connect EN pin to +V
IN
or any voltage source which is higher than 2V and less than 16V.
4. Turn on DC power supply and evaluation circuit will start.
5. Measure input voltage at the +V
IN
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 +V
OUT
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.
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.
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.
This datasheet 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.
