ADP1764-EVALZ/ADP1765-EVALZ User Guide
UG-1072
One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.com
Evaluating the
ADP1764
and
ADP1765
Low V
IN
, Low Noise, CMOS Linear Regulators
FEATURES
Full featured evaluation boards for
ADP1764
and
ADP1765
Input voltage range: 1.10 V to 1.98 V
Output current range:
ADP1764:
0 mA to 4 A
ADP1765:
0 mA to 5 A
Evaluation available on adjustable or fixed output voltage
Convenient test points for electrical measurements
Operating temperature range: −40°C to +125°C
EVALUATION BOARD PHOTOGRAPHS
ADDITIONAL EQUIPMENT NEEDED
Voltage source
Voltmeter
Ammeter
Electronic resistor load
GENERAL DESCRIPTION
The
ADP1764-1.0-EVALZ
and
ADP1765-1.0-EVALZ
fixed
evaluation boards and the
ADP1764-ADJ-EVALZ
and
ADP1765-
ADJ-EVALZ
adjustable evaluation boards demonstrate the
functionality of the
ADP1764
and the
ADP1765
series of linear
regulators.
Simple device measurements, such as line and load regulation,
dropout voltage, and ground current, are demonstrated with
only a single voltage supply, a voltmeter, an ammeter, and load
resistors.
Figure 1 and Figure 2 show the
ADP1765
evaluation boards;
the
ADP1764
fixed and adjustable evaluation boards are
identical to the
ADP1765.
For full details on the
ADP1764
and the
ADP1765
linear
regulators, see the
ADP1764
and the
ADP1765
data sheets, which
should be consulted in conjunction with this user guide when using
these evaluation boards.
15194-001
Figure 1. The
ADP1765-1.0-EVALZ
Fixed Board
(Identical to the
ADP1764-1.0-EVALZ)
Figure 2. The
ADP1765-ADJ-EVALZ
Adjustable Board
(Identical to the
ADP1764-ADJ-EVALZ)
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.
Rev. 0 | Page 1 of 9
15194-002
UG-1072
TABLE OF CONTENTS
Features .............................................................................................. 1
General Description ......................................................................... 1
Evaluation Board Photographs ....................................................... 1
Revision History ............................................................................... 2
Evaluation Board Hardware ............................................................ 3
Evaluation Board Configurations .............................................. 3
Output Voltage Measurements ................................................... 4
Line Regulation Measurements .................................................. 5
ADP1764-EVALZ/ADP1765-EVALZ User Guide
Load Regulation Measurements ..................................................5
Dropout Voltage Measurements..................................................5
Ground Current Measurements ..................................................5
Ground Current Consumption ...................................................6
Evaluation Board Schematics and Artwork ...................................7
Ordering Information .......................................................................9
Bill of Materials ..............................................................................9
REVISION HISTORY
1/2017—Revision 0: Initial Version
Rev. 0 | Page 2 of 9
ADP1764-EVALZ/ADP1765-EVALZ User Guide
EVALUATION BOARD HARDWARE
EVALUATION BOARD CONFIGURATIONS
The
ADP1764
and
ADP1765
evaluation boards come supplied
with different components, depending on the adjustable or fixed
version ordered. Components common to all versions are C1,
C2, C3, C4, C5, J1, and R2. Use R1 for the
ADP1764-ADJ-EVALZ
and
ADP1765-ADJ-EVALZ
evaluation boards. Figure 9 and
Figure 10 show the schematics of these evaluation board
configurations, and Table 1 describes the hardware components.
The
ADP1764-ADJ-EVALZ
and
ADP1765-ADJ-EVALZ
have
an output voltage range of 0.5 V to 1.5 V. The output voltage is
set to 1.0 V by the external 6.8 kΩ adjust resistor.
Calculate the output voltage (V
OUT
) by
V
OUT
=
A
D
× (R
ADJ
×
I
ADJ
)
where:
A
D
is the gain factor with a typical value of 2.99 between the
VADJ pin and VOUT pin.
R
ADJ
is the resistor connected between the VADJ pin and
ground.
I
ADJ
is the 50 µA constant current from the VADJ pin.
The
ADP1764-1.0-EVALZ
and
ADP1765-1.0-EVALZ
fixed
evaluation boards use a 1.0 V output model. Do not connect R1
for the fixed output option.
Calculate the start-up time of the regulator by
t
START-UP_FIXED
=
t
DELAY
+
V
REF
× (C
SS
/I
SS
)
t
START-UP_ADJ
=
t
DELAY
+
V
ADJ
× (C
SS
/I
SS
)
UG-1072
where:
t
DELAY
is a fixed delay of 100 µs.
V
REF
is a 0.5 V internal reference for the fixed output model option.
C
SS
is the soft start capacitance from the SS pin to GND.
I
SS
is the current sourced from the SS pin (10 µA).
V
ADJ
is the voltage at the VADJ pin equal to R
ADJ
× I
ADJ
.
Table 1. Evaluation Board Hardware Components
Component
U1
Description
ADP1764
and
ADP1765
low dropout linear
regulators.
For the fixed output option, U1 uses the 1.0 V
output option of the
ADP1764
and the
ADP1765.
For the adjustable output option, U1 uses the
adjustable option of the
ADP1764
and the
ADP1765
and is set to 1.0 V.
Input bypass capacitor (C
IN
), 22 µF, 0603 size.
Output capacitor (C
OUT
), 22 µF, 0603 size.
Soft start capacitor (C
SS
), 1000 pF, 0603 size.
(not installed in the evaluation board)
Regulator capacitor (C
REG
), 1 µF, 0603 size.
Reference capacitor (C
REG
), 1 µF, 0603 size.
Jumper (connects EN to VIN for automatic startup)
Adjust resistor (R
ADJ
) used to set the output
voltage of the adjustable version of the
ADP1764
and the
ADP1765.
Pull-up resistor (R
PULL-UP
) used for the open-drain
PG output pin.
C1
C2
C3
C4
C5
J1
R1
R2
Rev. 0 | Page 3 of 9
UG-1072
OUTPUT VOLTAGE MEASUREMENTS
ADP1764-EVALZ/ADP1765-EVALZ User Guide
VOLTMETER
VOLTAGE
SOURCE
+
+
–
1.29999
–
LOAD
Figure 3. Output Voltage Measurement Setup
Figure 3 shows how the evaluation boards can be connected to a
voltage source and a voltmeter for basic output voltage accuracy
measurements.
A resistor can be used as the load for the regulator. Ensure that
the resistor has a power rating that is adequate to handle the
power expected to dissipate across it. Use an electronic load as
an alternative. Ensure the voltage source can supply enough
current for the expected load levels.
Follow these steps to connect the evaluation board to a voltage
source and voltmeter:
1.
2.
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 on the evaluation board.
3.
4.
5.
Connect a load between the VOUT pad and one of the
GND pads on the evaluation board.
Connect the negative terminal of the voltmeter to one of
the GND pads on the evaluation board.
Connect the positive terminal of the voltmeter to the
VOUT pad on the evaluation board.
When these steps are completed, the voltage source can be turned
on. If J1 is inserted (connecting EN to VIN for automatic startup),
the regulator powers up.
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 ohmic voltage drops (IR).
Rev. 0 | Page 4 of 9
15194-003
ADP1764-EVALZ/ADP1765-EVALZ User Guide
LINE REGULATION MEASUREMENTS
For line regulation measurements, the change in the output of
the regulator is measured when the input is varied. For good
line regulation, the output must change as little as possible with
varying input levels. To ensure that the device is not in dropout
mode during line regulation measurement, V
IN
must be varied
between V
OUT
+ 0.2 V (or 1.1 V, whichever is greater) and 1.98 V.
For example, for an
ADP1764
or an
ADP1765
device with a fixed
1.3 V output, VIN must be varied between 1.5 V and 1.98 V. This
measurement can be repeated under different load conditions.
Figure 4 shows the typical line regulation performance of an
ADP1764
and an
ADP1765
with a fixed 1.3 V output.
1.306
1.305
1.304
1.303
I
LOAD
I
LOAD
I
LOAD
I
LOAD
I
LOAD
I
LOAD
= 0.1A
= 1.0A
= 2.0A
= 3.0A
= 4.0A
= 5.0A
UG-1072
DROPOUT VOLTAGE MEASUREMENTS
The dropout voltage can be measured using the configuration
shown in Figure 3. Dropout voltage is defined as the input to
output voltage differential when the input voltage is set to the
nominal output voltage. The
ADP1764
and the
ADP1765
only
enter dropout mode for output voltages of at least 1.2 V. For
lower voltage outputs, the
ADP1764
and the
ADP1765
enter
undervoltage lockout and shut down. The dropout voltage
increases with larger loads.
For accurate measurements, use a second voltmeter to monitor
the input voltage across the input capacitor. The input supply
voltage may need adjusting to account for IR drops, especially
when using large load currents. Figure 6 shows the typical curve
of dropout voltage measurements with different load currents.
0.10
0.09
0.08
0.07
V
OUT
(V)
1.302
1.301
V
DROP
(V)
1.58
1.66
1.74
V
IN
(V)
1.82
1.90
1.98
15194-004
1.300
1.299
1.298
1.297
1.296
1.50
0.06
0.05
0.04
0.03
0.02
0.01
1
LOAD CURRENT (A)
10
15194-006
Figure 4. Output Voltage vs. Input Voltage at V
OUT
= 1.3 V, T
A
= 25°C
0
0.1
LOAD REGULATION MEASUREMENTS
For load regulation measurements, the output of the regulator is
monitored while the load is varied. For good load regulation,
the output must change as little as possible with varying load.
The input voltage must be held constant during load regulation
measurement. The load current can be varied from 0 mA to 4 A
for the
ADP1764
and 0 mA to 5 A for the
ADP1765.
Figure 5
shows the typical load regulation performance of an
ADP1764
and an
ADP1765
with a fixed 1.3 V output for an input voltage
of 1.5 V.
1.304
1.303
1.302
1.301
Figure 6. Dropout Voltage vs. Load Current, V
OUT
= 1.3 V, T
A
= 25°C
GROUND CURRENT MEASUREMENTS
Figure 8 shows how the
ADP1764
and
ADP1765
evaluation
boards can connect to a voltage source and an ammeter for
ground current measurements.
A resistor can be used as the load for the regulator. Ensure the
resistor has a power rating that is adequate to handle the power
expected to be dissipated across it. Use an electronic load as an
alternative. Ensure that the voltage source can supply enough
current for the expected load levels.
Follow these steps to connect the evaluation board to a voltage
source and ammeter:
1.
2.
3.
4.
Connect the positive terminal of the voltage source to the
VIN pad on the evaluation board.
Connect the positive terminal of the ammeter to one of the
GND pads on the evaluation board.
Connect the negative terminal of the ammeter to the
negative terminal of the voltage source.
Connect a load between the VOUT pad on the evaluation
board and the negative terminal of the voltage source.
V
OUT
(V)
1.300
1.299
1.298
1.297
1.296
0.1
1
LOAD CURRENT (A)
10
15194-005
Figure 5. Output Voltage vs. Load Current at V
IN
= 1.5 V, V
OUT
= 1.3 V, T
A
= 25°C
When these connection steps are completed, the voltage source
can be turned on. If J1 is inserted (connecting EN to VIN for
automatic startup), the regulator powers up.
Rev. 0 | Page 5 of 9
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