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dc2041af
DEMO MANUAL DC2041A
Quick start proceDure
The DC2041 is easy to set up to evaluate the performance
of the LTC3255 with the shunt disabled. Refer to Figure 1
for proper measurement equipment setup with the shunt
disabled and follow the evaluation procedure below. To
evaluate the LTC3255 with the shunt enabled, go to the
SHUNT ENABLED section.
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. See Figure 2 for proper scope
probe technique.
1. Set the EN jumper, JP1, on the DC2041 board to the
ON position.
2. Set the SHUNT jumper, JP3, to the OFF position.
3. Set the V
OUT
jumper, JP2, to the desired output voltage.
NOTE. Do not set the V
OUT
jumper to the OPT setting un-
less the appropriate resistor is installed in R7. The V
OUT
jumper OPT position is to allow an alternate V
OUT
setting.
This can be accomplished by adding a resistor to R7 to
set the output to a desired voltage. Refer to the LTC3255
data sheet to calculate the appropriate value for R7.
4. With power off, connect a 0V to 48V, 100mA power
supply to V
IN
and GND with a voltmeter as shown in
Figure 1.
5. Turn on the V
IN
input power supply and increase the
supply until the V
OUT
voltage is in regulation and the
PGOOD voltage is pulled to V
OUT
.
NOTE. Make sure that the input voltages do not exceed 60V.
6. With V
IN
at least 1V above V
OUT
, increase the load on
V
OUT
from 0mA to 50mA and observe the input current.
The output ripple may also be observed using an oscil-
loscope with the probe connected as shown in Figure 2.
7. With a 50mA load on V
OUT
, increase V
IN
until the cur-
rent on V
IN
drops to approximately ½ the V
OUT
current.
8. Refer to the LTC3255 data sheet for more details on
how the LTC3255 operates.
9. When done, turn off all loads and power supplies.
