GE Industrial Solutions JRCW016A0R Orca Series - Manual (Page 8)

GE
Data Sheet
JRCW016A0R Orca Series; DC-DC Converter Power Modules
36–75 Vdc Input; 28.0Vdc Output; 16Adc Output
November 20, 2013 ©2012 General Electric Company. All rights reserved. Page 8
Feature Description (continued)
Remote sense
Remote sense minimizes the effects of distribution losses by
regulating the voltage at the remote-sense connections (see
Figure 11). For No Trim or Trim down application, the voltage
between the remote-sense pins and the output terminals
must not exceed the output voltage sense range given in the
Feature Specifications table i.e.:
[V
o
(+)–V
o
(-)] – [SENSE(+) – SENSE(-)]  2% of V
o,nom
The voltage between the Vo(+) and Vo(-) terminals must not
exceed the minimum output overvoltage shut-down value
indicated in the Feature Specifications table. This limit
includes any increase in voltage due to remote-sense
compensation and output voltage set-point adjustment (trim).
See Figure 11. If not using the remote-sense feature to
regulate the output at the point of load, then connect
SENSE(+) to V
o
(+) and SENSE(-) to V
o
(-) at the module.
Although the output voltage can be increased by both the
remote sense and by the trim, the maximum increase for the
output voltage is not the sum of both. The maximum increase
is the larger of either the remote sense or the trim. The
amount of power delivered by the module is defined as the
voltage at the output terminals multiplied by the output
current. When using remote sense and trim: the output
voltage of the module can be increased, which at the same
output current would increase the power output of the
module. Care should be taken to ensure that the maximum
output power of the module remains at or below the
maximum rated power.
Figure 11. Effective Circuit Configuration for Single-Module
Remote-Sense Operation Output Voltage.
Output Voltage Programming
Trimming allows the user to increase or decrease the output
voltage set point of a module. Trimming down is
accomplished by connecting an external resistor between the
TRIM pin and the SENSE(-) pin. Trimming up is accomplished
by connecting external resistor between the SENSE(+) pin and
TRIM pin. The trim resistor should be positioned close to the
module. Certain restrictions apply to the input voltage lower
limit when trimming the output voltage to the maximum. See
Figure 12 for the allowed input to output range when using
trim. If not using the trim down feature, leave the TRIM pin
open.
Figure 12. Output Voltage Trim Limits vs. Input Voltage.
Trim Down – Decrease Output Voltage
With an external resistor (R
adj_down
) between the TRIM and
SENSE(-) pins, the output voltage set point (V
o,adj
) decreases
(see Figure 13). The following equation determines the
required external-resistor value to obtain a percentage output
voltage change of %.
For output voltages:
V
O,nom
= 28V
Without –T Option With –T Option
 








k R
down adj
2
%
100
_
 








k R
down adj
11
%
1000
_
Where,
100 %
,
, 

 
nom o
desired nom o
V
V V
V
desired
= Desired output voltage set point (V).
Figure 13. Circuit Configuration to Decrease Output
Voltage.
Trim Up – Increase Output Voltage
With an external resistor ( R adj_up
) connected between the
SENSE(+) and TRIM pins , the output voltage set point ( V
o, ad j
)
increases (see Figure 14).
The following equation determines the required external-
resistor value to obtain a percentage output voltage change
of %.
15
20
25
30
35
35 40 45 50 55 60 65 70 75
Vin (V)
Vo
u
t (
V
)
Upper Trim Limit
Lower Trim Limit