Datasheet

EVAL-ADP170/ADP171
Rev. 0 | Page 4 of 8
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:
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 voltmeter to one
of the GND pads.
5. 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.
+
–
VOLTAGE SOURCE
V
IN
VOLTMETER
LOAD
V
OUT
+–
1.800
07723-004
Figure 4. Configuration for Output Voltage Measurements