QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 627
BOOST CONVERTER
2
5.
Increase the input voltage to 5.0V and apply 70mA
load and re-check regulation.
6.
Measure the DC input current at V
IN
= 5.0V and
I
OUT
= 70mA.
a.
For the DC627A-A, the input current should be
less than 215mA.
b.
For the DC627A-B, the input current should be
less than 225mA.
7.
Monitor the output voltage ripple. Refer to Figure 2
for the proper measurement technique.
8.
Measure the output ripple frequency.
a.
For the DC627A-A, the frequency should be be-
tween 1.0MHz and 1.7MHz.
b.
For the DC627A-B, the frequency should be be-
tween 2.1MHz and 3.9MHz.
NOTE:
If this circuit will be used in a hot plug applica-
tion, then be sure to measure the inrush current. The
maximum non-repetitive surge current the internal
schottky can handle is 1.5A. The inrush current can
be monitored by measuring the current through the
inductor when V
IN
is initially applied. Refer to the data
sheet for more details.
Figure 1.
Proper Measurement Equipment Setup
Figure 2.
Measuring Input or Output Ripple