EVAL-ADP1720_15 Datasheet, PDF (6/8 Pages) Analog Devices – Evaluation Board for the ADP1720

EVAL-ADP1720
LOAD REGULATION
For load regulation measurements, the regulator’s output is
monitored while the load is varied. For good load regulation,
the output must change as little as possible with varying load
levels. The input voltage must be held constant during this
measurement. The load current can be varied from 0 mA to
50 mA. Figure 7 shows the typical load regulation performance
of an ADP1720 with 5 V output for an input voltage of 12 V.
5.0015
5.0010
5.0005
5.0000
4.9995
4.9990
4.9985
4.9980
4.9975
4.9970
4.9965
0.01
0.1
1
10
100
I_LOAD (mA)
Figure 7. ADP1720 Load Regulation
DROPOUT VOLTAGE
Dropout voltage measurements can also be performed using
the configuration shown in Figure 5. 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 4 V. Dropout voltage increases with
larger loads. For more accurate measurements, a second voltage
meter can be used 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 8 shows a typical curve of dropout voltage measurements
with different load currents.
300
250
200
150
100
50
0
1
10
100
I_LOAD (mA)
Figure 8. Dropout Voltage vs. Load Current
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