JW050F, JW075F, JW100F, JW150F Power Modules:
dc-dc Converters; 36 to 75 Vdc Input, 3.3 Vdc Output; 33 W to 99 W
Data Sheet
April 2008
Output Voltage Set-Point Adjustment
(Trim)
Feature Descriptions (continued)
Remote Sense
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.
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.:
If not using the trim feature, leave the TRIM pin open.
[VO(+) – VO(–)] – [SENSE(+) – SENSE(–)] ð 0.5 V
With an external resistor between the TRIM and
SENSE(–) pins (Radj-down), the output voltage set point
(VO, adj) decreases (see Figure 22). The following equa-
tion determines the required external-resistor value to
obtain a percentage output voltage change of ý%.
The voltage between the VO(+) and VO(–) 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.
100
⎛
⎞
If not using the remote-sense feature to regulate the
output at the point of load, then connect SENSE(+) to
VO(+) and SENSE(–) to VO(–) at the module.
Radj-down = --------- – 2 kΩ
⎝
⎠
Δ%
The test results for this configuration are displayed in
Figure 23. This figure applies to all output voltages.
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.
With an external resistor connected between the TRIM
and SENSE(+) pins (Radj-up), the output voltage set
point (VO, adj) increases (see Figure 24).
The following equation determines the required exter-
nal-resistor value to obtain a percentage output voltage
change of ý%.
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.
(100 + 2Δ%)
(100 + Δ%)
VO
⎛
⎞
⎠
---------------------------------
Radj-up = -------------------------------------- –
kΩ
⎝
Δ%
1.225Δ%
The test results for this configuration are displayed in
Figure 25.
The voltage between the VO(+) and VO(–) 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.
SENSE(+)
SENSE(–)
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.
V
V
I
I
(+)
(–)
VO(+)
I
O
SUPPLY
LOAD
I
I
VO(–)
CONTACT
RESISTANCE
CONTACT AND
DISTRIBUTION LOSSES
8-651 (C).m
Figure 21. Effective Circuit Configuration for
Single-Module Remote-Sense Operation
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.
Lineage Power
11
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
