Data Sheet
JHC/JHW350 Power Module; dc-dc Converter
March 26, 2008
18 – 36Vdc or 36 – 75Vdc Input; 28Vdc Output; 350W
With an external resistor between the TRIM and
SENSE(-) pins (Radj-down), the output voltage set
point (Vo,adj) decreases (see Figure 18). The
following equation determines the required external-
resistor value to obtain a percentage output voltage
change of Δ%.
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
output voltage sense range given in the Feature
Specifications table i.e.:
For output voltages: 28V
100
⎛
⎜
⎞
⎠
Radj − down
=
− 2 KΩ
⎟
Δ%
⎝
[Vo(+) – Vo(-)] – [SENSE(+) – SENSE(-)] ≤5% of
Vo,nom
.
Where,
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
17. 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.
V
o, nom −Vdesired
Δ% =
×100
Vo, nom
Vdesired = 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 19).
The following equation determines the required
external-resistor value to obtain a percentage output
voltage change of Δ%.
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.
For output voltages: 28V
V
o, nom
*
100 + Δ%
)
(100 + 2Δ%)
Δ%
⎛
⎜
⎞
⎟
Radj − up
=
−
KΩ
1.225* Δ%
⎝
⎠
Where,
V
desired −Vo, nom
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
17.
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 17. Effective Circuit Configuration for
Single-Module Remote-Sense Operation Output
Voltage.
Output Voltage Set-Point Adjustment (Trim)
The amount of power delivered by the module is
defined as the voltage at the output terminals
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.
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
If not using the trim feature, leave the TRIM pin open.
LINEAGE POWER.
10
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
