Data Sheet
JRW017-070 Series Power Modules DC-DC Converters
36-75Vdc Input; 1.2Vdc to 12Vdc Output
July 21, 2008
Feature Descriptions (continued)
Remote sense (continued)
V
o, nom
*
100+Δ%
)
(100+2*Δ%)
Δ%
⎛
⎜
⎞
⎟
R
adj − up
=
−
KΩ
0.6*Δ%
⎝
⎠
Where,
V
o, nom −Vdesired
Δ% =
×100
Vo, nom
Vdesired = Desired output voltage set point (V).
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
48.
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.
Figure 47. 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. 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.
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.
If not using the trim feature, leave the TRIM pin open.
With an external resistor between the TRIM and
SENSE(-) pins (Radj-down), the output voltage set
point (Vo,adj) decreases (see Figure 36). The
following equation determines the required external-
resistor value to obtain a percentage output voltage
change of Δ%.
For output voltages: 1.2V – 12V
100
⎛
⎜
⎞
⎠
Radj − down
=
− 2 KΩ
⎟
Δ%
⎝
Where,
V
o, nom −Vdesired
Δ% =
×100
Vo, nom
Figure 48. Circuit Configuration to Decrease
Output Voltage.
V
desired = Desired output voltage set point (V).
With an external resistor connected between the
TRIM and SENSE(+) pins (Radj-up), the output
voltage set point (Vo,adj) increases (see Figure 37).
The following equation determines the required
external-resistor value to obtain a percentage output
voltage change of Δ%.
For output voltages: 1.5V – 12V
V
o, nom
*
(
100+ Δ%
)
(100+ 2*Δ%)
Δ%
⎛
⎜
⎞
⎟
Radj − up
=
−
KΩ
1.225*Δ%
⎝
⎠
Figure 49. Circuit Configuration to Increase
Output Voltage.
For output voltage: 1.2V
LINEAGE POWER
16
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
