1212 Tyco Electronics Corp.
Data Sheet
June 1999
dc-dc Converters; 36 to 75 Vdc Input, 24 Vdc Output; 50 W to 175 W
JW050H, JW075H, JW100H, JW150H, JW175H 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 giv en 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 e xceed 26.4 V. This limit includes an y increase
in voltage due to remote-sense compensation and out-
put voltage set-point adjustment (trim). See Figure 24.
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 b y 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 pow er of the module remains at or
below the maximum r ated po w er.
8-651 (C).m
Figure 24. Effective Circuit Configuration for
Single-Module Remote-Sense Operation
Output Voltage Set-P oint 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 posi-
tioned 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 25). 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 26. 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 27).
The following equation determines the required exter-
nal-resistor value to obtain a percentage output v oltage
change of
∆
%.
The test results for this configuration are displayed in
Figure 28.
The voltage between the V
O
(+) and V
O
(–) terminals
must not e xceed 26.4 V. This limit includes an y increase
in voltage due to remote-sense compensation and out-
put voltage set-point adjustment (trim). See Figure 24.
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 b y 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 pow er output
of the module. Care should be taken to ensure that the
maximum output pow er of the module remains at or
below the maxim um rated po w er.
V
O
(+)
SENSE(+)
SENSE(–)
V
O
(–)
V
I
(+)
V
I
(–)
I
O
LOAD
CONTACT AND
DISTRIBUTION LOSSES
SUPPLY I
I
CONTACT
RESISTANCE
Radj-down 100
∆%
----------2–
k
Ω
=
Radj-up VO100 ∆%+()
1.225∆%
-------------------------------------- 100 2∆%+()
∆%
----------------------------------
–
k Ω
=