2
Rev. 0
QUICK START PROCEDURE
DC2836A is easy to set up to evaluate the performance of
the LT7182S. Refer to Figure 3 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. See Figure 5 for the proper scope
technique.
1. Set an input power supply that is capable of 20V/18A.
Then turn off the supply.
2. With power off, connect the supply to the input termi-
nals VEMI and GND. Set default jumper position: SW1:
ON; SW2: ON
3. Turn on the power at the input.
NOTE: Make sure that the input voltage never exceeds 20V.
4. Check for the proper output voltages of 1.2V ±0.5%
(1.194V ~ 1.206V) and 3.3V ±0.5% (3.283V ~ 3.317V).
Turn off the power at the input.
5. Once the proper output voltage is established, connect
variable loads capable of sinking 6A at 1.2V and 3.3V
to the output terminals VOUT0/VOUT1 and GND. Set
the current for 0A.
a. If efficiency measurements are desired, ammeters
can be put in series with the output loads to measure
the DC2836A’s output currents.
b. Voltmeters can be placed across the output termi-
nals to get accurate output voltage measurements.
6. Turn on the power at the input.
NOTE: If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
7. Once the proper output voltages are established again,
adjust the load and/or input within the operating range
and observe the output voltage regulation, ripple volt-
age, efficiency and other desired parameters.
8. Connect the dongle and control the output voltages
from the GUI. See LTpowerPlay GUI for the LT7182S
Quick Start Guide for details.
NOTE: When measuring the output or input voltage rip-
ple, do not use the long ground lead on the oscilloscope
probe. See Figure 4 for the proper scope probe technique.
Short, stiff leads need to be soldered to the (+) and (–)
terminals of an output capacitor. The probe’s ground ring
needs to touch the (–) lead and the probe tip needs to
touch the (+) lead.
Figure 1. Efficiency vs Load Current at 1MHz Switching Frequency
V
OUT0
= 1.2
V
OUT1
= 3.3
LOAD CURRENT (A)
0
1
2
3
4
5
6
0
10
20
30
40
50
60
70
80
90
100
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
EFFICIENCY (%)
LOSS (W)
dc2836a F01a
EFFICIENCY
LOSS
f
SW
= 1MHz
V
IN
= 8V
V
IN
= 12V
V
IN
= 18V
EFFICIENCY
LOSS
f
SW
= 1MHz
V
IN
= 8V
V
IN
= 12V
V
IN
= 18V
LOAD CURRENT (A)
0
1
2
3
4
5
6
0
10
20
30
40
50
60
70
80
90
100
0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
EFFICIENCY (%)
LOSS (W)
dc2836a F01b
