EVAL-ADP1720: Evaluation Board for the ADP1720 Data Sheet PDF

EVAL-ADP1720: Evaluation Board for the ADP1720 Data Sheet PDF
Evaluation Board for the ADP1720
EVAL-ADP1720
FEATURES
GENERAL DESCRIPTION
Input voltage range: 4 V to 28 V
Output current range: 0 mA to 50 mA
Output voltage accuracy: ±1%
Operating temperature range: −40°C to +125°C
The ADP1720 evaluation board can be used to demonstrate the
functionality of the ADP1720 linear regulator. Depending on
what component combinations are used, the evaluation board
can be used for ADP1720 fixed output voltage devices and
ADP1720 adjustable output voltage devices.
Simple device measurements such as line and load regulation,
dropout, and ground current can be demonstrated with just a
single voltage supply, a voltage meter, a current meter, and load
resistors.
For more details about the ADP1720 linear regulators, visit
www.analog.com.
EVALUATION BOARD
EVAL-ADP1720
U1
GND
C1
GND
C2
R1
J1
R2
VIN
VOUT
GND
EN
GND/ADJ
GND
06768-001
J2
Figure 1.
Rev. 0
Evaluation boards are only intended for device evaluation and not for production purposes.
Evaluation boards are supplied “as is” and without warranties of any kind, express, implied, or
statutory including, but not limited to, any implied warranty of merchantability or fitness for a
particular purpose. No license is granted by implication or otherwise under any patents or other
intellectual property by application or use of evaluation boards. Information furnished by Analog
Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result
from its use. Analog Devices reserves the right to change devices or specifications at any time
without notice. Trademarks and registered trademarks are the property of their respective owners.
Evaluation boards are not authorized to be used in life support devices or systems.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2007 Analog Devices, Inc. All rights reserved.
EVAL-ADP1720
TABLE OF CONTENTS
Features .............................................................................................. 1
Load Regulation ............................................................................6
General Description ......................................................................... 1
Dropout Voltage ............................................................................6
Evaluation Board .............................................................................. 1
Ground Current Measurements ......................................................7
Revision History ............................................................................... 2
Ground Current Consumption ...................................................7
Evaluation Board Hardware and Schematic ................................. 3
Ordering Information.......................................................................8
Evaluation Board Configurations................................................... 4
Bill of Materials..............................................................................8
ADP1720 Adjustable Output ...................................................... 4
Ordering Guide .............................................................................8
ADP1720 Fixed Output ............................................................... 4
ESD Caution...................................................................................8
Output Voltage Measurements ....................................................... 5
Line Regulation............................................................................. 5
REVISION HISTORY
6/07—Revision 0: Initial Version
Rev. 0 | Page 2 of 8
EVAL-ADP1720
EVALUATION BOARD HARDWARE AND SCHEMATIC
GND
VIN
GND
C1
U1
GND/ADJ
J1
EN
1
GND/ADJ GND
8
2
IN
GND
7
3
OUT
GND
6
4
EN
GND
5
J2
R1
C2
GND
VOUT
GND
06768-002
R2
Figure 2. Evaluation Board Schematic
Table 1. Evaluation Board Hardware Components
Component
U1 1
C1
C2
R1, R2 2
J1
J23
1
2
3
Function
Linear regulator
Input capacitor
Output capacitor
Output voltage adjust resistors
Jumper
Jumper
Description
ADP1720 Low Dropout Linear Regulator.
1 μF Input Bypass Capacitor.
1 μF Output Capacitor. Required for stability and transient performance.
External Resistors. Used to set VOUT with the adjustable version of ADP1720.
Jumper. Connects EN to VIN for automatic startup.
Jumper. Connects the GND/ADJ pin to GND for fixed version devices.
Component varies depending on which evaluation board type is ordered.
Components present only on boards with ADP1720 adjustable output devices.
Components present only on boards with ADP1720 fixed output devices.
Rev. 0 | Page 3 of 8
EVAL-ADP1720
EVALUATION BOARD CONFIGURATIONS
ADP1720 ADJUSTABLE OUTPUT
Evaluation boards that come supplied with ADP1720 adjustable
output voltage option devices have the additional R1 and R2
resistors included. Figure 3 shows the schematic of this
evaluation board configuration.
ADP1720 FIXED OUTPUT
Fixed output voltage evaluation boards are available in 3.3 V
and 5 V options. For fixed output devices, J2 is inserted to
connect the GND/ADJ pin to ground. Figure 4 shows the
schematic of this evaluation board configuration.
ADP1720
J2
VIN
ADP1720
1
GND
ADJ
8
R1
2
IN
GND
7
3
OUT
GND
6
4
EN
GND
5
C1
J1
VOUT
GND
8
2
IN
GND
7
3
OUT
GND
6
4
EN
GND
5
C2
U1
Figure 4. ADP1720 Fixed Output
U1
C2
J1
VOUT
06768-003
VIN
GND
C1
ADJUSTABLE
R2
1
Figure 3. ADP1720 Adjustable Output
The output voltage is set based on the following equation:
VOUT = 1.225 V (1 + R1/R2)
For example, if R1 = 15 kΩ and R2 = 10 kΩ, then VOUT
is 3.06 V.
Rev. 0 | Page 4 of 8
06768-004
The ADP1720 evaluation boards come supplied with different
components depending on which version is ordered.
Components common to all versions are C1, C2, and J1.
EVAL-ADP1720
OUTPUT VOLTAGE MEASUREMENTS
VOLTAGE SOURCE
+
VOLTAGE METER
V
EVAL-ADP1720
_
_
U1
GND
C1
+
GND
C2
R1
J1
R2
VIN
VOUT
LOAD
GND
GND/ADJ
EN
06768-005
J2
GND
Figure 5.
1.
2.
3.
4.
5.
Connect the negative terminal (−) of the voltage source to
one of the GND pads on the evaluation board.
Connect the positive terminal (+) of the voltage source to
the VIN pad of the evaluation board.
Connect a load between the VOUT pad and one of the
GND pads.
Connect the negative terminal (−) of the voltage meter to
one of the GND pads, and the positive terminal (+) of the
voltage meter to the VOUT pad.
The voltage source can now be turned on. If J1 is inserted
(this connects EN to VIN for automatic startup), then the
regulator powers up.
For line regulation measurements, the regulator’s output is
monitored while its input is varied. For good line regulation,
the output must change as little as possible with varying input
levels. To ensure the device is not in dropout during this
measurement, VIN must be varied between VOUTNOM + 0.5 V
(or 4 V, whichever is greater) to VINMAX. For an ADP1720 with
5 V output, this means VIN needs to be varied between 5.5 V
and 28 V. This measurement can be repeated under different
load conditions. Figure 6 shows the typical line regulation
performance of an ADP1720 with 5 V output.
If large load currents are used, then the user must connect the
voltage meter as close as possible to the output capacitor to
reduce the effects of IR drops.
5.010
ILOAD = 10µA
ILOAD = 100µA
ILOAD = 1mA
ILOAD = 10mA
ILOAD = 25mA
ILOAD = 50mA
5.008
5.006
5.004
5.002
5.000
4.998
4.996
4.994
06768-006
Follow these steps to connect to a voltage source and voltage meter:
LINE REGULATION
VOUT (V)
Figure 5 shows how the evaluation board can be connected to a
voltage source and a voltage meter for some basic output voltage
accuracy measurements. A resistor can be used as the load for
the regulator. Ensure the resistor has a power rating adequate
to handle the power expected to be dissipated across it. An electronic load can be used as an alternative. Ensure the voltage source
used can supply adequate current for the expected load levels.
4.992
4.990
0
5
10
15
20
VIN (V)
Figure 6. ADP1720 Line Regulation
Rev. 0 | Page 5 of 8
25
30
EVAL-ADP1720
LOAD REGULATION
DROPOUT VOLTAGE
For load regulation measurements, the regulator’s output is
monitored while the load is varied. For good load regulation,
the output must change as little as possible with varying load
levels. The input voltage must be held constant during this
measurement. The load current can be varied from 0 mA to
50 mA. Figure 7 shows the typical load regulation performance
of an ADP1720 with 5 V output for an input voltage of 12 V.
Dropout voltage measurements can also be performed using
the configuration shown in Figure 5. Dropout voltage is defined
as the input-to-output voltage differential when the input
voltage is set to the nominal output voltage. This applies only
for output voltages above 4 V. Dropout voltage increases with
larger loads. For more accurate measurements, a second voltage
meter can be used to monitor the input voltage across the input
capacitor. The input supply voltage may need to be adjusted to
account for IR drops, especially if large load currents are used.
Figure 8 shows a typical curve of dropout voltage measurements
with different load currents.
5.0015
5.0010
5.0005
300
4.9995
4.9990
250
4.9985
VDROPOUT (mV)
4.9980
4.9975
06768-007
4.9970
4.9965
0.01
0.1
1
10
100
ILOAD (mA)
200
150
100
50
Figure 7. ADP1720 Load Regulation
0
06768-008
VOUT (V)
5.0000
1
10
ILOAD (mA)
Figure 8. Dropout Voltage vs. Load Current
Rev. 0 | Page 6 of 8
100
EVAL-ADP1720
GROUND CURRENT MEASUREMENTS
CURRENT
METER
_
μA
EVAL-ADP1720
+
U1
GND
C1
GND
C2
VOLTAGE SOURCE
+
R1
_
J1
R2
LOAD
VIN
VOUT
EN
GND
06768-009
J2
GND
GND/ADJ
Figure 9.
largest load level (50 mA). Figure 10 shows the typical ground
current consumption for various load levels.
1200
1000
800
IGND (µA)
Follow these steps to connect to a voltage source and current meter:
1.
2.
3.
4.
5.
Connect the positive terminal (+) of the voltage source to
the VIN pad on the evaluation board.
Connect the positive terminal (+) of the current meter to
one of the GND pads of the evaluation board.
Connect the negative terminal (−) of the current meter to
the negative (−) terminal of the voltage source.
Connect a load between the VOUT pad of the evaluation
board and the negative (−) terminal of the voltage source.
The voltage source can now be turned on. If J1 is inserted
(this connects EN to VIN for automatic startup), then the
regulator powers up.
GROUND CURRENT CONSUMPTION
Ground current measurements are a way of determining how
much current the regulator’s internal circuits are consuming,
while performing the regulation function. To be efficient, the
regulator must consume as little current as possible. Typically,
the regulator consumes maximum current when supplying its
600
400
200
0
0.01
06768-010
Figure 9 shows how the evaluation board can be connected
to a voltage source and a current meter for ground current
measurements. A resistor can be used as the load for the
regulator. Ensure the resistor has a power rating adequate to
handle the power expected to be dissipated across it. An electronic
load can be used as an alternative. Ensure the voltage source
used can supply adequate current for the expected load levels.
0.1
1
10
100
ILOAD (mA)
Figure 10. Ground Current vs. Load Current
When the device is disabled (EN = 0 V), ground current is
reduced to less than 1 μA.
Note that larger ground current levels are observed when using
an evaluation board with R1 and R2 present.
Rev. 0 | Page 7 of 8
EVAL-ADP1720
ORDERING INFORMATION
BILL OF MATERIALS
Table 2.
Qty
1
1
1
1
2
1
Reference Designator
C1
C2
R1
R2
J1, J2
U1
Description
Capacitor, MLCC, 1 μF, 50 V, 0805, X7R
Capacitor, MLCC, 1 μF, 16 V, 0805, X7R
Resistor, 15 kΩ, 1%, 0805
Resistor, 10 kΩ, 1%, 0805
Header, single, STR, 2 pins
ADP1720, IC, LDO regulator
ORDERING GUIDE
Model
ADP1720-EVALZ1
ADP1720-3.3-EVALZ1
ADP1720-5-EVALZ1
1
Manufacturer/Vendor
Murata or equivalent
Murata or equivalent
Vishay Dale or equivalent
Vishay Dale or equivalent
Digi-Key, Corp.
Analog Devices, Inc.
ESD CAUTION
Description
Evaluation Board with Adjustable Output
ADP1720
Evaluation Board with 3.3 V Fixed Output
ADP1720
Evaluation Board with 5 V Fixed Output
ADP1720
Z = RoHS Compliant Part.
©2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
EB06768-0-6/07(0)
Rev. 0 | Page 8 of 8
Vendor Part No.
GRM21BR71H105KA12
GRM21BR71C105KA01
CRCW080515K0FKEA
CRCW080510K0FKEA
S1012E-36-ND
ADP1720ARMZ-5-R7
ADP1720ARMZ-3.3-R7
ADP1720ARMZ-R7
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