Datasheet

UG-116 Evaluation Board User Guide
Rev. A | Page 8 of 12
LOAD
VOLTAGE SOURCE
+ –
–+
AMMETER
0.00112
0
8933-016
Figure 15. Ground Current Measurement Setup, LFCSP
GROUND CURRENT CONSUMPTION
Figure 13 and Figure 14 show 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 that is 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
can supply enough current for the expected load levels.
Ground current measurements can determine how much current
the internal circuits of the regulator consume while the circuits
perform the regulation function. To be efficient, the regulator
must consume as little current as possible. Typically, the regulator
uses the maximum current when supplying its largest load level
(200 mA). Figure 16 shows the typical ground current consump-
tion for various load levels at V
OUT
= 2.8 V and T
A
= 25°C.
Use the following steps to connect to a voltage source and
ammeter:
When the device is disabled (EN = GND), ground current
drops to less than 1 μA.
1. Connect the positive terminal (+) of the voltage source to
the VIN pad on the evaluation board.
10
100
1000
3.10 3.50 3.90 4.30 4.70 5.10 5.50
GROUND CURRENT (µA)
V
IN
(V)
LOAD = 10µA
LOAD = 100µA
LOAD = 1mA
LOAD = 10mA
LOAD = 100mA
LOAD = 200mA
08933-012
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.
When these connection steps are completed, the voltage source
can be turned on. If J1 is inserted (connecting EN to VIN for
automatic startup), the regulator powers up.
Figure 16. Ground Current vs. Input Voltage, V
OUT
= 2.8 V, T
A
= 25°C