Datasheet

UG-230 Evaluation Board User Guide
Rev. 0 | Page 4 of 10
VIN TO VOUT RESISTANCE (RDS
ON
)
RDS
ON
can be measured using the configuration shown in
Figure 6 and Figure 7. RDS
ON
is defined as the input-to-output
voltage differential divided by 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.
0.25
0
0.05
0.10
0.15
0.20
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5
RDS
ON
(Ω)
V
IN
(V)
10mA
100mA
200mA
400mA
800mA
1000mA
09562-005
Figure 5. RDS
ON
vs. Input Voltage, WLCSP
+
–
VOLTMETER
1.99711
+
–
VOLTAGE SOURCE
LOAD
0
9562-006
Figure 6. LFCSP RDS
ON
Measurement