Data Sheet
March 26, 2008
JHC/JHW350 Power Module; dc-dc Converter
18 – 36Vdc or 36 – 75Vdc Input; 28Vdc Output; 350W
Safety Considerations
All Versions - 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., UL60950, CSA C22.2
No. 60950-00, and EN 60950 (VDE 0805):2001-12.
“W” Versions only - For end products connected to –
48V dc, or –60Vdc nominal DC MAINS (i.e. central
office dc battery plant), no further fault testing is
required. *Note: -60V dc nominal battery plants are
not available in the U.S. or Canada.
All Versions - For all input voltages, other than DC
MAINS, where the input voltage is less than 60V dc, if
the input meets all of the requirements for SELV,
then:
The output may be considered SELV. Output
voltages will remain within SELV limits even
with internally-generated non-SELV voltages.
Single component failure and fault tests were
performed in the power converters.
One pole of the input and one pole of the
output are to be grounded, or both circuits are
to be kept floating, to maintain the output
voltage to ground voltage within ELV or SELV
limits.
“W” Versions only - For all input sources, other than
DC MAINS, where the input voltage is between 60
and 75V dc (Classified as TNV-2 in Europe), the
following must be meet, if the converter’s output is to
be evaluated for SELV:
The input source is to be provided with
reinforced insulation from any hazardous voltage,
including the ac mains.
One Vi pin and one Vo pin are to be reliably
earthed, or both the input and output pins are to
be kept floating.
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.
All Versions - The power module has ELV (extra-low
voltage) outputs when all inputs are ELV.
All flammable materials used in the manufacturing of
these modules are rated 94V-0.
fast-acting (or time-delay) fuse in the unearthed lead
for their respective versions.
Feature Descriptions
Overcurrent Protection
To provide protection in a fault output overload
condition, the module is equipped with internal
current-limiting circuitry and can endure current limit
for few seconds. If overcurrent persists for few
seconds, the module will shut down and remain latch-
off. The overcurrent latch is reset by either cycling the
input power or by toggling the on/off pin for one
second. If the output overload condition still exists
when the module restarts, it will shut down again. This
operation will continue indefinitely until the
overcurrent condition is corrected.
An auto-restart option is also available.
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
during a logic high and on during a logic low. Negative
logic, device code suffix "1," is the factory-preferred
configuration. To turn the power module on and off,
the user must supply a switch to control the voltage
between the on/off terminal (Von/off) and the V
I
(-)
terminal. The switch can be an open collector or
equivalent (see Figure 16). A logic low is Von/off = 0
V to 0.5 V. The maximum Ion/off during a logic low is
1 mA. The switch should maintain a logic-low voltage
while sinking 1 mA. During a logic high, the maximum
Von/off generated by the power module is 5 V. The
maximum allowable leakage current of the switch at
Von/off = 5V is 50 µA. If not using the remote on/off
feature, perform one of the following to turn the unit
on:
For negative logic, short ON/OFF pin to V
IN
(-).
For positive logic: leave ON/OFF pin open.
Figure 16. Remote On/Off Implementation.
The input to these units is to be provided with a
maximum 20A (JHW series) and 30A (JHC series)
LINEAGE
POWER
9
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
