2
dc2221af
DEMO MANUAL DC2221A
Quick start proceDure
Demonstration circuit DC2221A is easy to set up to evalu-
ate the performance of the LTC3807EFE. Refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
NOTE. When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the input or output voltage
ripple by touching the probe tip directly across the V
IN
or V
OUT
and GND terminals or directly across relevant
capacitor. See Figure 2 for proper scope probe technique.
1. Place jumper JP1 in the ON position.
2. With power off, connect the input power supply to V
IN
and GND.
3. Turn on the power at the input. Check for the proper
output voltage:
V
OUT
= 11.9V to 12.4V
NOTE. If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
4. Once the proper output voltages are established, adjust
the load within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
Figure 1. Proper Measurement Equipment Setup
Figure 2. Measuring Input or Output Ripple Across Terminals or Directly Across Bulk Capacitor
LOAD
+
–
I
OUT
V
IN
SUPPLY
+
–
I
IN
+
–
V
OUT
GND
C
OUT
GND
VIN