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Page 20
External Trim (J2-5/P2-5)
Output voltage can be trimmed using an optional factory-installed Trim potentiometer or with the Trim
pin (see Figure 11). The Trim potentiometer is located on the ConverterPAC™. If the Trim potentiometer
has not been ordered, the Trim pin must be used. When using the Trim pin, the Trim limits are
determined by the DC-DC converter used on the ConverterPAC. Maximum Trim ranges are 10% above
the nominal converter voltage and 50% below the nominal converter voltage (except 10, 12 and 15V
outputs which are 10% below nominal) as measured from the output studs or output connector of
the power supply.
Note:
The combined effects of module trim up, remote sense and dynamic-load step may cause the module to trip
OVP. (Tripping OVP will require cycling input power to the supply off, then on).
The Trim pin on J2/P2 can be used to control the output voltage. It is referenced to the –Sense pin on J2
and can be controlled by either a resistor network or an external voltage source. To increase an output
voltage above its nominal, it is necessary to increase the voltage at the Trim pin above the internal
reference voltage (V
REF
). The reverse is true to decrease an output voltage.
Note:
Converters are sometimes pretrimmed at the factory if a nonstandard output voltage is requested. If using a
nonstandard voltage or if a ConverterPAC is ordered with a Trim option, the resistor calculations will differ from those
on Page 21. Please consult the factory for assistance.
Output Module
V
REF
R
TH
VI-200™ / VI-J00™
≥
3.3V
2.50V
10.0kW
VI-200 / VI-J00 < 3.3V
0.97V
3.88kW
Maxi (Pre-Defined)
1.23V
1.0kW
Maxi (User-Defined)
1.23V
Consult Factory
Figure 11
External trim
(Remote Sense)
Load
+P +Out
P2-7 +Sense
P2-6 –Sense
–P –Out
Use 22-24AWG Twisted Pair Wires
R5
V
REF
P2-5
R6
R8
R7
To Error
Amplifier
R4
R3
R2
R1
+
+
V
2
V
1
–
–
R
TH
Use 22-24AWG
Twisted Pair Wires
Table 1
Module internal
reference voltages and
Thevenin resistances