
Tyco Electronics Corp
11
Data Sheet
July 1999 
dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W to 150 W
JW050A, JW075A, JW100A, JW150A Power Modules:
Feature Descriptions 
(continued)
Remote Sense
Remote sense minimizes the effects of distribution 
losses by regulating the voltage at the remote-sense 
connections. The voltage between the remote-sense 
pins and the output terminals must not exceed the out-
put voltage sense range given in the Feature Specifica-
tions table, i.e.:
[V
O
(+) – V
O
(–)] – [SENSE(+) – SENSE(–)] 
≤
 0.5 V
The voltage between the V
O
(+) and V
O
(–) terminals 
must not exceed the minimum value of the output over-
voltage protection. This limit includes any increase in 
voltage due to remote-sense compensation and output 
voltage set-point adjustment (trim). See Figure 21.
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. Consult the factory if you 
need to increase the output voltage more than the 
above limitation.
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.
8-651 (C).m
Figure 21. Effective Circuit Configuration for
Single-Module Remote-Sense Operation
Output Voltage Set-Point Adjustment (Trim)
Output voltage trim allows the user to increase or 
decrease the output voltage set point of a module. This 
is accomplished by connecting an external resistor 
between the TRIM pin and either the SENSE(+) or 
SENSE(–) pins. The trim resistor should be positioned 
close to the module.
If not using the trim feature, leave the TRIM pin open.
With an external resistor between the TRIM and 
SENSE(–) pins (R
adj-down
), the output voltage set point 
(V
O, adj
) decreases (see Figure 22). The following equa-
tion determines the required external-resistor value to 
obtain a percentage output voltage change of 
%.
The test results for this configuration are displayed in 
Figure 23. This figure applies to all output voltages.
With an external resistor connected between the TRIM 
and SENSE(+) pins (R
adj-up
), the output voltage set 
point (V
O, adj
) increases (see Figure 24). 
The following equation determines the required exter-
nal-resistor value to obtain a percentage output voltage 
change of 
%.
%
+
(
%
The test results for this configuration are displayed in 
Figure 25. 
The voltage between the V
O
(+) and V
O
(–) terminals 
must not exceed the minimum value of the output over-
voltage protection. This limit includes any increase in 
voltage due to remote-sense compensation and output 
voltage set-point adjustment (trim). See Figure 21.
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. Consult the factory if you 
need to increase the output voltage more than the 
above limitation.
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.
V
O
(+)
SENSE(+)
SENSE(–)
V
O
(–)
V
I
(+)
V
I
(–)
I
O
LOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY
I
I
CONTACT
RESISTANCE
R
adj-down
100
---%
2
–
 
 k
  
=
R
adj-up
V
 100
-------1.225
)
100
---------------%
2
%
+
(
)
–
 
  k
  
=