Q48SB9R650NRFA Datasheet, PDF (7/12 Pages) Delta Electronics, Inc. – Delphi Series Q48SB, 500W Bus Converter DC/DC Power Modules: 48V in, 9.6V/55A 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 typical
100uF electrolytic capacitor (ESR > 0.1 Ω at 100 kHz, -40^oC to
100^oC.) 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 50A 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.
DS_Q48SB9R650_07102006
7