Datasheet
EVAL-ADP1706/ADP1707/ADP1708
Rev. 0 | Page 5 of 8
OUTPUT VOLTAGE MEASUREMENTS
GND
GND GNDEN
GND
SS/ADJ/TRK
VIN VOUT
J1
R2
R1
U1
C1 C2
C3
ANALOG
DEVICES
ADP1706/ADP1707/ADP1708
SOIC 8
+
_
VOLTAGE SOURCE
+
_
VOLTMETER
V
LOAD
06934-007
Figure 7. Output Voltage Measurement
Figure 7 shows how the evaluation board can be connected to
a voltage source and a voltage meter 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
adequate to handle 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.
Follow these steps to connect to a voltage source and voltage meter:
1. Connect the negative terminal (−) of the voltage source to
one of the GND pads on the evaluation board.
2. Connect the positive terminal (+) of the voltage source to
the VIN pad of the evaluation board.
3. Connect a load between the VOUT pad and one of the
GND pads.
4. 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.
5. 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.
If the load current is large, the user needs to connect the voltage
meter as close as possible to the output capacitor to reduce the
effects of IR drops.
LINE REGULATION
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 that the device is not in dropout during this
measurement, VIN must be varied between VOUT
NOM
+ 0.6 V
(or 2.5 V, whichever is greater) and VIN
MAX
. For example, for
an
ADP1706 with fixed 3.3 V output, VIN needs to be varied
between 3.9 V and 5.5 V. This measurement can be repeated
under different load conditions.
Figure 8 shows the typical line
regulation performance of an ADP1706 with fixed 3.3 V output.
3.8 4.2 4.6 5.0 5.4
V
IN
(V)
V
OUT
(V)
3.25
3.26
3.27
3.28
3.29
3.30
3.31
3.32
I
LOAD
= 300mA
I
LOAD
= 100mA
I
LOAD
= 10mA
I
LOAD
= 100µA
I
LOAD
= 1A
I
LOAD
= 500mA
06934-008
Figure 8. Output Voltage vs. Input Voltage