Datasheet

UWE-100-120W Series
Wide Input, Isolated Eighth-Brick DC-DC Converters
MDC_UWE-100-120W.C02 Page 31 of 34
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A single resistor connected from the Trim to the +Output, or +Sense where
applicable, will increase the output voltage in this confi guration. A resistor con-
nected from the Trim to the –Output, or –Sense where applicable, will decrease
the output voltage in this confi guration.
Trim adjustments greater than the specifi ed range can have an adverse
affect on the converter's performance and are not recommended. Excessive
voltage differences between V
OUT and Sense, in conjunction with trim adjust-
ment of the output voltage, can cause the overvoltage protection circuitry to
activate (see Performance Specifi cations for overvoltage limits). Power derating
is based on maximum output current and voltage at the converter’s output
pins. Use of trim and sense functions can cause output voltages to increase,
thereby increasing output power beyond the converter's specifi ed rating or
cause output voltages to climb into the output overvoltage region. Therefore:
(V
OUT at pins) x (IOUT) <= rated output power
Note: Resistor values are in k. Adjustment accuracy is subject to resistor
tolerances and factory-adjusted output accuracy. V
O = desired output voltage.
LOAD
R2
+VOUT
+VIN
–VIN
ON/OFF
CONTROL
TRIM
+SENSE
–VOUT
–SENSE
Figure 8. Trim Connections to Decrease Output Voltages
1M
5-20
TURNS
LOAD
+VOUT
+VIN
–VIN
ON/OFF
CONTROL
TRIM
+SENSE
–VOUT
–SENSE
Figure 6. Trim Connections Using a Trimpot
LOAD
R1
+VOUT
+VIN
–VIN
ON/OFF
CONTROL
TRIM
+SENSE
–VOUT
–SENSE
Figure 7. Trim Connections to Increase Output Voltages Using a Fixed Resistor
UP
VO – 3.3
R
T (kΩ) =
–10.2
13.3(VO – 1.226)
3.3 – V
O
RT (kΩ) =
–10.2
16.31
DOWN
3.3 Volt Output
UP
VO – 5
R
T (kΩ) =
–10.2
20.4(VO – 1.226)
5 – V
O
RT (kΩ) =
–10.2
25.01
DOWN
5 Volt Output
UP
VO – 12
R
T (kΩ) =
–10.2
49.6(VO – 1.226)
12 – V
O
RT (kΩ) =
–10.2
60.45
DOWN
12 Volt Output
Trim Equations
Trim Up Trim Down