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Signal Ground (J3-1)
Signal Ground on J3-1 is an isolated secondary ground reference for J3 status signals. It is used to
provide a reference point for the Power Good circuitry and is not the same as Earth Ground on input
power connector J9.
VCC In (J3-4)
The VCC In on J3-4 is an input that re5V either from the J10 Auxiliary VCC, or from another
source. Input current to this pin is limited by an internal resistor to 3mA. If the J10 Auxiliary VCC
is connected to VCC In on J3- 4, then at least one J10 Signal Ground must be connected to Signal
Ground on J3-1.
+Sense/–Sense (J2-2 and J2-3)
The +Sense on J2-2 should be connected to the +Power Out, and the –Sense on J2-3 to the –Power
Out terminal. Do not reverse or leave the Sense pins open. Sense pins can be terminated locally at
the output of the power supply, in which case the power supply will provide regulation at the output
terminals. The voltage appearing at the load may drop slightly due to voltage drop in the power cables.
If it is necessary to compensate for voltage drop along the output power cables, this termination should
be made close to the output load. Compensation of up to 0.5V (0.25V per lead) can be obtained. Use
twisted pair 22 – 24AWG wire for this purpose.
For DualPACs
™
, the +Sense pins are available on connectors designated as J2A-2 and J2B-2 for outputs
A and B, respectively. –Sense pins are on J2A-3 and J2B-3, respectively. These pins are also duplicated
on the power connectors J1A and J1B.
External Trim (J2-1)
Output voltage can be trimmed using an optional factory-installed Trim potentiometer or with the Trim
pin (see Figure 9). 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.
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 (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. Standard
voltages include 2, 3.3, 5, 12, 15, 24, 28, and 48V. If using a nonstandard voltage, or if a ConverterPAC is ordered
with a Trim option, the resistor calculations will differ from those below. Please consult the factory
for assistance.
Figure 8
Sense Leads
(Remote Sense)
Load
(Local Sense)
+P +OUT
J2-2 +Sense
J2-3 –Sense
–P –OUT
Use 22-24AWG Twisted Pair Wires
