JW050R Lineage Power, JW050R Datasheet - Page 12

• Manufacturer Part Number: JW050R
• Manufacturer: Lineage Power

dc-dc Converters; 36 to 75 Vdc Input, 28 Vdc Output; 50 W to 150
Safety Considerations
For safety-agency approval of the system in which the
power module is used, the power module must be
installed in compliance with the spacing and separation
requirements of the end-use safety agency standard,
i.e., UL1950, CSA C22.2 No. 950-95, and VDE 0805
(EN60950, IEC950).
If the input source is non-SELV (ELV or a hazardous
voltage greater than 60 Vdc and less than or equal to
75 Vdc), for the module’s output to be considered
meeting the requirements of safety extra-low voltage
(SELV), all of the following must be true:
n
n
n
n
Note: Do not ground either of the input pins of the
The power module has extra-low voltage (ELV) outputs
when all inputs are ELV.
The input to these units is to be provided with a maxi-
mum 20 A normal-blow fuse in the ungrounded lead.
Feature Descriptions
Overcurrent Protection
To provide protection in a fault (output overload) condi-
tion, the unit is equipped with internal current-limiting
circuitry and can endure current limiting for an unlim-
ited duration. At the point of current-limit inception, the
unit shifts from voltage control to current control. If the
output voltage is pulled very low during a severe fault,
the current-limit circuit can exhibit either foldback or tai-
lout characteristics (output current decrease or
increase). The unit operates normally once the output
current is brought back into its specified range.
12
12
The input source is to be provided with reinforced
insulation from any hazardous voltages, including the
ac mains.
One V
both the input and output pins are to be kept floating.
The input pins of the module are not operator acces-
sible.
Another SELV reliability test is conducted on the
whole system, as required by the safety agencies, on
the combination of supply source and the subject
module to verify that under a single fault, hazardous
voltages do not appear at the module’s output.
module without grounding one of the output pins.
This may allow a non-SELV voltage to appear
between the output pin and ground.
I
pin and one V
O
pin are to be grounded or
Remote On/Off
Two remote on/off options are available. Positive logic
remote on/off turns the module on during a logic-high
voltage on the ON/OFF pin, and off during a logic low.
Negative logic remote on/off turns the module off dur-
ing a logic high and on during a logic low. Negative
logic (code suffix “1”) is the factory-preferred configura-
tion.
To turn the power module on and off, the user must
supply a switch to control the voltage between the
on/off terminal and the V
switch can be an open collector or equivalent (see
Figure 29). A logic low is V
maximum I
should maintain a logic-low voltage while sinking 1 mA.
During a logic high, the maximum V
the power module is 15 V. The maximum allowable
leakage current of the switch at V
If not using the remote on/off feature, do one of the
following:
n
n
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.:
For negative logic, short ON/OFF pin to V
For positive logic, leave ON/OFF pin open.
[V
Figure 29. Remote On/Off Implementation
O
(+) – V
V
I
on/off
on/off
on/off
O
(–)] – [SENSE(+) – SENSE(–)] ð 0.5 V
during a logic low is 1 mA. The switch
ON/OFF
V
V
I
I
(+)
(–)
I
(–) terminal (V
on/off
SENSE(+)
SENSE(–)
= 0 V to 1.2 V. The
on/off
V
V
O
O
on/off
(+)
(–)
= 15 V is 50 µA.
on/off
Lineage Power
generated by
I
April 2008
(–).
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8-720 (C).c
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