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
Remote On/Off
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).
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.
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:
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 VI(–) terminal (Von/off). The
switch can be an open collector or equivalent (see
Figure 20). A logic low is Von/off = 0 V to 1.2 V. The
maximum Ion/off during a logic low is 1 mA. The switch
should maintain a logic-low voltage while sinking 1 mA.
n The input source is to be provided with reinforced
insulation from any hazardous voltages, including the
ac mains.
During a logic high, the maximum Von/off generated by
the power module is 15 V. The maximum allowable
leakage current of the switch at Von/off = 15 V is 50 µA.
n One VI pin and one VO pin are to be grounded or
both the input and output pins are to be kept floating.
n The input pins of the module are not operator acces-
sible.
If not using the remote on/off feature, do one of the
following:
n 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.
n For negative logic, short ON/OFF pin to VI(–).
n For positive logic, leave ON/OFF pin open.
I
on/off
Note: Do not ground either of the input pins of the
module without grounding one of the output pins.
This may allow a non-SELV voltage to appear
between the output pin and ground.
ON/OFF
V
on/off
SENSE(+)
(+)
V
O
The power module has extra-low voltage (ELV) outputs
when all inputs are ELV.
LOAD
V
O
(–)
V
V
I
I
(+)
(–)
SENSE(–)
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
8-720 (C).c
Figure 20. Remote On/Off Implementation
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.
10
Lineage Power
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
