JW075B5 Lineage Power, JW075B5 Datasheet - Page 8

• Manufacturer Part Number: JW075B5
• Manufacturer: Lineage Power

JW075A5, JW075B5, JW075C5 Power Modules: dc-dc Converters:
Design Considerations
Input Source Impedance
The power module should be connected to a low
ac-impedance input source. Highly inductive source
impedances can affect the stability of the power mod-
ule. For the test configuration in Figure 14, a 33 µF
electrolytic capacitor (ESR < 0.7
mounted close to the power module helps ensure sta-
bility of the unit. For other highly inductive source
impedances, consult the factory for further application
guidelines.
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., UL 1950, 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 meet-
ing the requirements of safety extra-low voltage
(SELV), all of the following must be true:
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.
8 8
36 Vdc to 75 Vdc Input; 5 Vdc, 12 Vdc, or 15 Vdc Output; 75 W
The input source is to be provided with reinforced
insulation from any hazardous voltages, including the
ac mains.
One V
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 both
at 100 kHz)
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.
Remote On/Off
The remote on/off turns the module on during a logic-
high voltage on the ON/OFF pin, and off during a logic
low.
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 14). A logic low is V
imum 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, leave the ON/OFF
pin open.
Figure 14. Remote On/Off Implementation
on/off
V
I
on/off
on/off
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 max-
on/off
V
V
O
O
on/off
(+)
(–)
= 15 V is 50 µA.
on/off
generated by
Data Sheet
April 2008
). The
Lineage Power
8-720 (C).c
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