ADP170/ADP171评估板 PDF

Evaluation Board for the ADP170/ADP171
EVAL-ADP170/ADP171
FEATURES
GENERAL DESCRIPTION
Input voltage range: 1.6 V to 3.6 V
Output current range: 0 mA to 300 mA
Output voltage accuracy: ±1%
Operating temperature range: −40°C to +125°C
The ADP170/ADP171 evaluation board is used to demonstrate
the functionality of the ADP170/ADP171 linear regulators.
Simple device measurements such as line and load regulation,
dropout, and ground current can be demonstrated with just a
single voltage supply, a voltmeter, a current meter, and load
resistors.
For more details about the ADP170/ADP171 linear regulators,
visit www.analog.com.
07723-001
EVALUATION BOARD
Figure 1. 5-Lead TSOT Layout
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.
www.analog.com
Tel: 781.329.4700
Fax: 781.461.3113
©2009 Analog Devices, Inc. All rights reserved.
EVAL-ADP170/ADP171
TABLE OF CONTENTS
Features .............................................................................................. 1 Load Regulation ............................................................................5 General Description ......................................................................... 1 Dropout Voltage ............................................................................5 Evaluation Board .............................................................................. 1 Ground Current Measurements ......................................................6 Revision History ............................................................................... 2 Ground Current Consumption ...................................................7 Evaluation Board Hardware and Schematics ................................ 3 Ordering Information .......................................................................8 Evaluation Board Configurations .............................................. 3 Bill of Materials ..............................................................................8 Output Voltage Measurements ....................................................... 4 Ordering Guide .............................................................................8 Line Regulation ............................................................................. 5 ESD Caution...................................................................................8 REVISION HISTORY
1/09—Revision 0: Initial Version
Rev. 0 | Page 2 of 8
EVAL-ADP170/ADP171
EVALUATION BOARD HARDWARE AND SCHEMATICS
VIN = 2.3V
VIN
2
GND
3
EN
VOUT
U1
5
ADP170
C1 C3 C4 J1
C2 C5 C6
NC
4
07723-002
The ADP170/ADP171 evaluation boards come supplied with
different components, depending on which version is ordered.
Components common to all versions are C1 through C6 and J1.
The J2, R1, and R2 components are populated on the adjustable
ADP171 version only; these components are not populated on
the ADP170. C1, C3, and C4 are input capacitors, and C2, C5,
and C6 are output capacitors. These capacitors have different
size footprints to facilitate evaluating the regulator using a
wide variety of components. Figure 2 shows the schematic of
ADP170 evaluation board configuration. Figure 3 shows the
schematic of ADP171 evaluation board configuration.
VOUT = 1.8V
1
Figure 2. ADP170 Evaluation Board Schematic
VOUT = 0.5V(1 + R1/R2)
VIN = 2.3V
1
VIN
2
GND
VOUT
U1
5
ADP171
C1 C3 C4 J1
J2
C2 C5 C6
R1
3
EN
ADJ
4
R2
Figure 3. ADP171 Evaluation Board Schematic
Table 1. Evaluation Board Hardware Components
Component
U1 1
C1
C2
C3
C4
C5
C6
J1
J2
TP1
TP2
1
Function
Linear regulator
0805 size input capacitor
0402 size output capacitor
0603 size input capacitor
0402 size input capacitor
0603 size output capacitor
0805 size input capacitor
Jumper
Jumper
Test point
Test point
Description
ADP170/ADP171 low dropout linear regulator.
Not populated.
Not populated.
1 μF input bypass capacitor.
Not populated.
1 μF output capacitor. Required for stability and transient performance.
Not populated.
Jumper. Connects EN to VIN for automatic startup.
Jumper. Connects the VOUT to the resistor feedback network.
Test point closest to VIN pin.
Test point closest to VOUT pin.
Component depends on the evaluation board type ordered.
Rev. 0 | Page 3 of 8
07723-003
EVALUATION BOARD CONFIGURATIONS
EVAL-ADP170/ADP171
OUTPUT VOLTAGE MEASUREMENTS
Figure 4 shows how the evaluation board can be connected to a
voltage source and a voltmeter for basic measurements of the
output voltage accuracy. A resistor can be used as the load for
the regulator. Ensure that the resistor has an adequate power
rating for handling the power expected to be dissipated across
it. An electronic load can also be used as an alternative. Ensure
that the voltage source can supply enough current for the expected
load levels.
Use the following steps to connect to a voltage source and
voltmeter:
2.
3.
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.
5.
Connect the negative terminal (−) of the voltmeter to one
of the GND pads.
Connect the positive terminal (+) of the voltmeter to the
pad closest to the VOUT pin.
The voltage source can then be turned on. If J1 is inserted
(which connects EN to VIN for automatic startup), the
regulator powers up. For ADP170, Jumper J2 need not be
inserted as shown in Figure 4. The current from the external
resistor divider network when there is adjustable voltage output
(as with the ADP171) should be subtracted from the ground
current measured.
If the load current is large, the user must connect the voltmeter
as close as possible to the output capacitor to reduce the effects
of IR drops due to trace resistance.
VIN
VOUT
VOLTAGE SOURCE
VOLTMETER
1.800
–
+
+
–
LOAD
07723-004
1.
4.
Figure 4. Configuration for Output Voltage Measurements
Rev. 0 | Page 4 of 8
EVAL-ADP170/ADP171
LINE REGULATION
DROPOUT VOLTAGE
For line regulation measurements, the output of the regulator is
monitored while its input varies. For good line regulation, the
output (VOUT) must change as little as possible with varying
input (VIN) levels. To ensure that the device is not in dropout
during this measurement, VIN must be varied between VOUTNOM
+ 0.5 V (or 1.6 V, whichever is greater) and VINMAX. For example,
for an ADP170 with fixed 1.8 V output, VIN needs to be varied
between 2.3 V and 5.5 V. This measurement can be repeated
under different load conditions. Figure 5 shows the typical line
regulation performance of an ADP170 with fixed 1.8 V output.
Dropout voltage can be measured using the configuration
shown in Figure 4. Dropout voltage is defined as the input-tooutput voltage differential when the input voltage is set to the
nominal output voltage. This applies only for output voltages
greater than 1.6 V. Dropout voltage increases with larger loads.
For more accurate measurements, use a second voltmeter to
monitor the input voltage across the input capacitor. The input
supply voltage may need to be adjusted to account for IR drops
due to trace resistance, especially if large load currents are used.
Figure 7 shows a typical curve of dropout voltage measurements
with different load currents.
1.805
70
1.804
TA = 25°C
60
DROPOUT VOLTAGE (mV)
1.802
1.801
1.800
1.799
LOAD = 100µA
LOAD = 1mA
2.3
2.5
LOAD = 10mA
LOAD = 100mA
2.7
2.9
3.1
LOAD = 200mA
LOAD = 300mA
3.3
3.5
VIN (V)
1
10
100
Figure 7. Dropout Voltage vs. Load Current
For load regulation measurements, the output of the regulator is
monitored while the load varies. For good load regulation, the
output must change as little as possible with varying load current.
The input voltage must be held constant during this measurement.
The load current can be varied from 0 mA to 150 mA. Figure 6
shows the typical load regulation performance of an ADP170 with
fixed 1.8 V output for an input voltage of 2.3 V.
1.804
1.803
1.802
1.801
1.800
1.799
07723-006
VOUT (V)
20
LOAD CURRENT (mA)
LOAD REGULATION
0.1
30
0
Figure 5. Output Voltage vs. Input Voltage
1.798
0.01
40
10
07723-007
1.798
2.1
50
1
10
100
1k
LOAD CURRENT (mA)
Figure 6. Output Voltage vs. Load Current
Rev. 0 | Page 5 of 8
1k
07723-012
VOUT (V)
1.803
EVAL-ADP170/ADP171
GROUND CURRENT MEASUREMENTS
Figure 8 shows how the evaluation board can be connected to a
voltage source and an ammeter to measure ground currents. A
resistor can be used as the load for the regulator. Ensure that the
resistor has an adequate power rating for handling the power
expected to be dissipated across it. An electronic load can be
used as an alternative. Ensure that the voltage source used can
supply enough current for the expected load levels.
2.
Use the following steps to connect to a voltage source and
ammeter:
The voltage source can then be turned on. If J1 is inserted
(which connects EN to VIN for automatic startup), the
regulator powers up. For ADP170, Jumper J2 need not be
inserted as shown in Figure 8.
Connect the positive terminal (+) of the voltage source to
the VIN pad on the evaluation board.
4.
VIN
GROUND CURRENT
VOLTAGE SOURCE
AMMETER
0.035
+
–
–
+
07723-008
1.
3.
Connect the positive terminal (+) of the ammeter to one of
the GND pads of the evaluation board.
Connect the negative terminal (−) of the ammeter to the
negative (−) terminal of the voltage source.
Connect a load between the negative (−) terminal of the
voltage source and the pad closest to the VOUT pin of the
evaluation board.
Figure 8. Configuration for Ground Current Measurements
Rev. 0 | Page 6 of 8
EVAL-ADP170/ADP171
GROUND CURRENT CONSUMPTION
180
Ground current measurements can determine how much
current the internal circuits of the regulator are consuming
while the circuits perform the regulation function. To be
efficient, the regulator needs to consume as little current as
possible. Typically, the regulator uses the maximum current
when supplying its largest load level (300 mA). Figure 9 shows
the typical ground current consumption for various load levels
at an input voltage of 2.3 V. When the device is disabled (EN =
GND), the ground current drops to less than 1 μA.
160
120
100
80
60
40
07723-009
GROUND CURRENT (µA)
140
20
0
0.01
0.1
1
10
100
LOAD CURRENT (mA)
Figure 9. Ground Current vs. Load Current
Rev. 0 | Page 7 of 8
1000
EVAL-ADP170/ADP171
ORDERING INFORMATION
BILL OF MATERIALS
Table 2.
Qty
2
1
1
1
Reference Designator
C1, C2
J1
U1
Description
Capacitor, MLCC, 1 μF, 10 V, 0603, X5R
Header, single, STR, two pins
IC, LDO regulator
Component depends on the evaluation board type ordered.
ORDERING GUIDE
Model
ADP170-1.8-EVALZ1
ADP171-EVALZ1
1
Manufacturer/Vendor
Murata or equivalent
Digi-Key Corp.
Analog Devices, Inc.
Output
Voltage (V)
1.8
1.0
ESD CAUTION
Description
Evaluation Board
Evaluation Board
Z = RoHS Compliant Part.
©2009 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
EB07723-0-1/09(0)
Rev. 0 | Page 8 of 8
Vendor Part No.
GRM188R61A105KA61
S1012E-36-ND
ADP170/ADP171 1
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