Q48SL1R535NRFA Datasheet, PDF (8/13 Pages) Delta Electronics, Inc. – Delphi Series Q48SL, 100W Quarter Brick Family DC/DC Power Modules: 48V in, 1.5V/35A out

DESIGN CONSIDERATIONS
Input Source Impedance
The impedance of the input source connecting to the
DC/DC power modules will interact with the modules and
affect the stability. A low ac-impedance input source is
recommended. If the source inductance is more than a few
µH, we advise adding a 10 to 100 µF electrolytic capacitor
(ESR < 0.7 Ω at 100 kHz) mounted close to the input of the
module to improve the stability.
Layout and EMC Considerations
Delta’s DC/DC power modules are designed to operate in a
wide variety of systems and applications. For design
assistance with EMC compliance and related PWB layout
issues, please contact Delta’s technical support team. An
external input filter module is available for easier EMC
compliance design. Application notes to assist designers
in addressing these issues are pending release.
Safety Considerations
The power module must be installed in compliance with the
spacing and separation requirements of the end-user’s
safety agency standard, i.e., UL60950, CAN/CSA-C22.2 No.
60950-00 and EN60950:2000 and IEC60950-1999, if the
system in which the power module is to be used must meet
safety agency requirements.
Basic insulation based on 75 Vdc input is provided between
the input and output of the module for the purpose of
applying insulation requirements when the input to this
DC-to-DC converter is identified as TNV-2 or SELV. An
additional evaluation is needed if the source is other than
TNV-2 or SELV.
When the input source is SELV circuit, the power module
meets SELV (safety extra-low voltage) requirements. If the
input source is a hazardous voltage which is greater than 60
Vdc and less than or equal to 75 Vdc, for the module’s output
to meet SELV requirements, all of the following must be met:
The input source must be insulated from the ac mains
by reinforced or double insulation.
The input terminals of the module are not operator
accessible.
If the metal baseplate is grounded, one Vi pin and one
Vo pin shall also be grounded.
A SELV reliability test is conducted on the system
where the module is used, in combination with the
module, to ensure that under a single fault, hazardous
voltage does not appear at the module’s output.
When installed into a Class II equipment (without
grounding), spacing consideration should be given to the
end-use installation, as the spacing between the module
and mounting surface have not been evaluated.
The power module has extra-low voltage (ELV) outputs
when all inputs are ELV.
This power module is not internally fused. To achieve
optimum safety and system protection, an input line fuse
is highly recommended. The safety agencies require a
normal-blow fuse with 20A maximum rating to be installed
in the ungrounded lead. A lower rated fuse can be used
based on the maximum inrush transient energy and
maximum input current.
Soldering and Cleaning Considerations
Post solder cleaning is usually the final board assembly
process before the board or system undergoes electrical
testing. Inadequate cleaning and/or drying may lower the
reliability of a power module and severely affect the
finished circuit board assembly test. Adequate cleaning
and/or drying is especially important for un-encapsulated
and/or open frame type power modules. For assistance on
appropriate soldering and cleaning procedures, please
contact Delta’s technical support team.
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DS_Q48SL1R535_01192007