Datasheet

Evaluation Board User Guide UG-116
Rev. A | Page 5 of 12
08933-015
VOLTMETER
1.99711
+–
VOLTAGE SOURCE
LOAD
+–
Figure 9. Output Voltage Measurement Setup, LFCSP
This measurement can be repeated under different load
conditions. Figure 10 shows the typical line regulation
performance of an ADP151 with a 2.8 V output.
Figure 7 and Figure 8 show how the evaluation board 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 that is 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.
2.77
2.78
2.79
2.80
2.81
2.82
2.83
3.10 3.50 3.90 4.30 4.70 5.10 5.50
V
OUT
(V)
V
IN
(V)
LOAD = 10µA
LOAD = 100µA
LOAD = 1mA
LOAD = 10mA
LOAD = 100mA
LOAD = 200mA
08933-007
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.
Figure 10. Output Voltage (V
OUT
) vs. Input Voltage (V
IN
) at T
A
= 25°C
5. Connect the positive terminal (+) of the voltmeter to the
VOUT pad.
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 this measure-
ment. The load current can be varied from 0 mA to 200 mA.
Figure 11 shows the typical load regulation performance of an
ADP151 with a 2.8 V output for an input voltage of 3.2 V.
When these steps are completed, the voltage source can be
turned on. If J1 is inserted (connecting EN to VIN for auto-
matic 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 IR drops.
LINE REGULATION MEASUREMENTS
For line regulation measurements, the output of the regulator
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 mode during
this measurement, V
IN
must be varied between V
OUT
nominal +
0.4 V (or 2.2 V, whichever is greater) and V
IN
maximum. For
example, for an ADP151 with a 2.8 V output, V
IN
needs to be
varied between 3.2 V and 5.5 V.