unr-3.3/8-d5t C&D Technologies., unr-3.3/8-d5t Datasheet - Page 5

• Manufacturer Part Number: unr-3.3/8-d5t
• Description: 8 And 10 Amp Dc/dc Converters
• Manufacturer: C&D Technologies.

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A trimpot can be used to determine the value of a single fixed resistor which
should be connected, as shown in Figure 4, between the Trim pin and
+Output to trim down the output voltage, or between the Trim pin and Output
Return to trim up the output voltage. Fixed resistors should be metal-film
types with absolute TCR’s less than 100ppm/°C to ensure stability.
The equations below can be used as starting points for selecting specific
trim-resistor values. Recall that untrimmed devices are guaranteed to be
between ±1% and ±2% accurate, depending on model. See Performance
and Functional Specifications.
Note: Install either a fixed trim-up resistor or a fixed trim-down resistor
depending upon desired output voltage.
Figure 4. Trim Connections Using Fixed Resistors
INPUT
RETURN
+INPUT
+INPUT
INPUT
RETURN
Figure 3. Trim Connections Using a Trimpot
+OUTPUT
OUTPUT
RETURN
+OUTPUT
OUTPUT
RETURN
TRIM
TRIM
20kΩ
5-10
Turns
Trim
Down
Trim Up
LOAD
LOAD
UNR-1.8/10-D5T
UNR-1.8/10-D5SM
UNR-2.5/10-D5T
UNR-2.5/10-D5SM
UNR-3.3/8-D5T
UNR-3.3/8-D5SM
UNR-3.3/10-D5T
UNR-3.3/10-D5SM
UNR-3.3/8-D12T
UNR-3.3/8-D12SM
UNR-3.3/10-D12T
UNR-3.3/10-D12SM
Note: Resistor values are in kΩ. Accuracy of adjustment is subject to
Single Output, Non-Isolated, 5 or 12V
tolerances of resistors and factory-adjusted output accuracy.
Technical enquiries email: [e-mail], tel:
V
O
= desired output voltage.
UNR D5/D12 Series
R
R
R
R
T
R
T
T
R
T
R
R
DOWN
DOWN
DOWN
DOWN
T
T
T
T
UP
UP
UP
UP
(kΩ) =
(kΩ) =
(kΩ) =
(kΩ) =
(kΩ) =
(kΩ) =
(kΩ) =
(kΩ) =
8 and 10 Amp DC/DC Converters
7.5(V
7.5(V
7.5(V
2.49(V
V
V
V
V
O
O
O
3.14
9.41
9.5
O
9.47
2.5 – V
3.3 – V
– 3.3
3.3 – V
1.8 – V
– 1.8
– 3.3
– 2.5
UNR18-33W.B01 Page 5 of 10
O
O
O
IN
O
– 1.26)
– 1.27)
– 1.26)
– 1.26)
to 1.8/2.5/3.3V
O
O
O
O
–1.0
–1.0
–1.74
–1.74
[phone]
–1.74
–1.0
–1.0
–1.74
OUT