Vicor Mini MegaPAC AC-DC Switcher - Manual (Page 18)

UG:110 vicorpower.com Applications Engineering: 800 927.9474 Page 18
Interface Connections (Cont.)
External Trim (J2-1)
Output voltage can be trimmed using an optional factory-installed Trim potentiometer or
with the Trim pin (see Figure 10). 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 V, 12 V, 13.8 V and 15 V 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. (See page 19 for information on restart).
The Trim pin on J2 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 (Vref). The reverse is true to decrease an
output voltage.
Note: Converters are sometimes pretrimmed at the factory if a nonstandard output voltage is requested.
Standard voltages include 2 V, 3.3 V, 5 V, 10 V, 12 V, 15 V, 24 V, 28 V, and 48 V. If using a nonstandard
voltage, or if a ConverterPAC is ordered with a Trim option, the resistor calculations will differ from those on
Page 19. Please consult the factory for assistance.
Output Module V
ref
R
TH
VI-200/VI-J00 ³3.3 V 2.50 V 10.0 kW
VI-200/VI-J00 <3.3 V 0.97 V 3.88 kW
(Remote Sense)
Load
(Local Sense)
+P +Out
J2-2 +Sense
J2-3 -Sense
-P -Out
Use 22-24 AWG
Twisted Pair Wires
Figure 9.
Sense Leads
Table 1.
Module Internal Reference
Voltages and Thevenin
Resistances