Datasheet

EVAL-ADP190
Rev. 0 | Page 5 of 8
GROUND CURRENT MEASUREMENT
Figure 6 shows how the evaluation board can be connected to a
voltage source and an ammeter for ground current 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 be
used as an alternative. Ensure that the voltage source used can
supply enough current for the expected load levels. If voltmeters
are connected at the input or output terminals, subtract the
current resulting from the shunt resistance of the voltmeter for
accurate ground current measurement.
Follow these steps to connect to a voltage source and ammeter:
1. Connect the positive terminal (+) of the voltage source to
the VIN pad on the evaluation board.
2. Connect the positive terminal (+) of the ammeter to one of
the GND pads of the evaluation board.
3. Connect the negative terminal (−) of the ammeter to the
negative (−) terminal of the voltage source.
4. Connect a load between the VOUT pad of the evaluation
board and the negative (−) terminal of the voltage source.
The voltage source can now be turned on. If J1 is inserted
(connecting EN to VIN for automatic startup), the regulator
powers up.
GROUND CURRENT CONSUMPTION
Ground current measurement is a way of determining how
much current the internal circuits of the regulator are consum-
ing, while performing the power switch function. To be efficient,
the power switch needs to consume as little current as possible.
Figure 5 shows the typical ground current consumption for various
load levels.
07862-006
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
3.2 3.61.2 1.7 2.2 2.7
V
IN
(V)
GROUND CURRENT (µA)
I
LOAD
= 10mA
I
LOAD
= 100mA
I
LOAD
= 250mA
I
LOAD
= 350mA
I
LOAD
= 500mA
Figure 5. Ground Current vs. Input Voltage, V
IN
VOLTAGE SOURCE
VIN
AMMETER
GND CURRENT
0.035
LOAD
07862-005
Figure 6. Ground Current Measurement