Rev. D
TECHNICAL DATASHEET
LV12S20-100
Output Voltage Trim: (5V, 12V, 15V, and 20V Models)
The output is adjustable +/–10% of rated output voltage. To trim the output voltage down, place the trim resistor
between the Trim and -Rs pins (Figure 5). To trim the output voltage up, place the trim resistor between the Trim
and +Rs pins (Figure 4).
The value of the trim resistor with respect to the desired output voltage (Vo) can be derived from the following
formulas, or looked up on the trim table (Table 2).
V
onom
U
1
−
R
1
⋅
V
o
−
R
lim
RTH
=
V
o
−
V
onom
V
o
−
V
onom
R
1
⋅
V
o
⋅
RTL
=
R
1
⋅
V
o
−
R
lim
V
onom
−
V
o
(in Kohms)
(in Kohms)
Figure 4: Trim Up
+V
out
+Rs
RTH
Pins Facing Down
Trim
Figure 5: Trim Down
+V
out
+Rs
R
load
Pins Facing Down
Trim
R
load
RTL
-Rs
-V
out
-Rs
-V
out
Table 2: Trim Equations for LV Series (5V, 12V, 15V, and 20V Models)
Vonom
20.000
Percent
Trim
1%
2%
3%
4%
5%
6%
7%
8%
9%
10%
(888) 597-WALL
U1
2.500
Trim Low
Vo
RTL
19.800 500.78
19.600 245.28
19.400 160.11
19.200 117.53
19.000 91.98
18.800 74.95
18.600 62.78
18.400 53.66
18.200 46.56
18.000 40.88
R1
5.11
Rlim RTH to +Rs
5.11
RTL to -Rs
Trim High
Vo
RTH
20.200 3607.66
All in Kohms
20.400 1819.16
20.600 1222.99
20.800 924.91
21.000 746.06
21.200 626.83
21.400 541.66
21.600 477.79
21.800 428.10
22.000 388.36
Note that while decreasing the output voltage, the
maximum output current still remains at 5A, and
while increasing the output voltage, the output
current is reduced to maintain a total output power
at 100 W.
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