UG-136 Evaluation Board User Guide
Rev. A | Page 4 of 12
V
IN
TO V
OUT
RESISTANCE (RDS
ON
)
0
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
1.2 1.6 2.0 2.4 2.8 3.2 3.6
V
IN
(V)
RDS
ON
Ω)
08996-005
I
OUT
= 10mA
I
OUT
= 100mA
I
OUT
= 200mA
I
OUT
= 500mA
I
OUT
= 1000mA
RDS
ON
can be measured using the configurations shown in
Figure 7 and Figure 8. RDS
ON
is defined as the input-to-output
voltage differential divided by the load current.
The voltmeter reading divided by the load current value gives the
equivalent RDS
ON
value. For more accurate measurements, a
second voltmeter 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 5 shows a typical curve of RDS
ON
measurements
with different load currents for the 4-ball WLCSP package and
Figure 6 shows a typical curve of RDS
ON
measurements with
different load currents for the 6-lead LFCSP.
Use the following steps to connect to a voltage source and
voltmeter:
Figure 5. 4-Ball WLCSP RDS
ON
vs. Input Voltage, V
IN
1. Connect the negative terminal (−) of the voltage source to
one of the GND pads on the evaluation board.
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0
1.2 1.4 1.6 1.8 2.0 2.2 2.4 3.63.43.23.02.82.6
RDS
ON
Ω)
V
IN
(V)
08996-014
I
OUT
= 10mA
I
OUT
= 50mA
I
OUT
= 100mA
I
OUT
= 200mA
I
OUT
= 500mA
I
OUT
= 1000mA
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 the
VOUT pad.
5. Connect the positive terminal (+) of the voltmeter to the
VIN pad.
When these steps are completed, the voltage source can be
turned on. If J1 is inserted (connecting EN to VIN for
automatic startup), the switch powers up.
Figure 6. 6-Lead LFCSP RDS
ON
vs. Input Voltage, V
IN
