Delta Electronics Delphi S36SE - Manual (Page 6)

DS_S36SE05003_07312008
6
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. Below is the example of
using Delta latest FL75L07 A input filter tested with
S36SE series to meet class B in CISSPR 22.
Schematic and Components List
C3
S36SE
Series
C1 C2
FL75L07 A
Load
Vin
C1 is 22uF/100V, low ESR Aluminum cap;
C2 is 2.2uF ceramic cap;
C3 is 22nF ceramic capacitor;
FL75L07 A is Delta input EMI filter module.
Test Result
Test result is in compliance with CISPR 22 class B, which
is shown as below:
Vin=48V, Po=15W, average mode
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: