JFW48S3.3-4000 Datasheet, PDF (6/16 Pages) Wall Industries,Inc. – DC/DC Converter

TECHNICAL DATASHEET
JFW48S3.3-4000
External Trim Adjustment
Output voltage set point adjustment allows the user to increase or decrease the output voltage set point of a
module. This is accomplished by connecting an external resistor between the TRIM pin and either the +Vout or
-Vout pins. With an external resistor between the TRIM and +Vout pin, the output voltage set point decreases.
With an external resistor between the TRIM and -Vout pin, the output voltage set point increases.
Rup
=
5110 ∗ 2.5
Vo⁺ − 2.5 − 0.8
−
2050
(in Ω)
Vo⁺ is the desired up output voltage
Rdown
=
(Vo ^− − 2.5) ∗ 5110
Vout − (Vo ^− )
−
2050
(in Ω)
Vo^- is the desired down output voltage
-Vin
+Vin
Figure 7
-Vout
RT1
Trim
RT2
+Vout
Trim
1%
2%
3%
4%
5%
6%
7%
8%
9%
10%
Table 3 Trim Resistor Values
Vo⁺
3.333V
3.366V
3.399V
3.432V
3.465V
3.498V
3.531V
3.564V
3.597V
3.63V
R_up
385.071 kΩ
191.511 kΩ
126.99 kΩ
94.73 kΩ
75.374 kΩ
62.47 kΩ
53.253 kΩ
46.34 kΩ
40.963 kΩ
36.662 kΩ
Vo^–
3.267V
3.234V
3.201V
3.168V
3.135V
3.102V
3.069V
3.036V
3.003V
2.97V
R_down
116.719 kΩ
54.779 kΩ
34.133 kΩ
23.810 kΩ
17.616 kΩ
13.486 kΩ
10.537 kΩ
8.325 kΩ
6.604 kΩ
5.228 kΩ
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www.wallindustries.com
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