Datasheet
EVAL-ADP1752/ADP1753
Rev. 0 | Page 5 of 12
LINE REGULATION
For line regulation measurements, the regulator output is moni-
tored 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
OUTNOM
+ 0.4 V
(or + 1.6 V, whichever is greater) and V
INMAX
. For example, for
an ADP1752 with fixed 1.5 V output, V
IN
needs to be varied
between 1.9 V and 3.6 V. This measurement can be repeated
under different load conditions. Figure 4 shows the typical line
regulation performance of an ADP1752 with fixed 1.5 V output.
1.520
1.515
1.510
1.505
1.500
1.495
1.490
1.485
1.480
–40 –5 25 85 125
OUTPUT VOLTAGE (V)
JUNCTION TEMPERATURE (°C)
LOAD = 10mA
LOAD = 100mA
LOAD = 400mA
LOAD = 800mA
07739-105
Figure 4. Output Voltage vs. Input Voltage
LOAD REGULATION
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 loads.
The input voltage must be held constant during this measure-
ment. The load current can be varied from 500 A to 800 mA.
Figure 5 shows the typical load regulation performance of an
ADP1752 with fixed 1.5 V output for an input voltage of 1.9 V.
1.520
1.515
1.510
1.505
1.500
1.495
1.490
1.485
1.480
10 100 1k
OUTPUT VOLTAGE (V)
LOAD CURRENT (mA)
07739-106
Figure 5. Output Voltage vs. Load Current
DROPOUT VOLTAGE
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. This applies only for output voltages
above 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,
especially if large load currents are used. Figure 6 shows a typical
curve of dropout voltage measurements with different load
currents.
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
1 10 100 1K
LOAD CURRENT (mA)
DROPOUT VOLTAGE (V)
1.6V
2.5V
07739-011
Figure 6. Dropout Voltage vs. Load Current