SFME28-461
EMI FILTER
10 AMP
F
EATURES
• Fully qualified to Class H or K
• Passive components for
maximum tolerance in space
environments
• –55° to +125°C operation
• Up to 10 amps of
throughput current
• Up to 50 dB attenuation
at 500 kHz.
• Compliant to MIL-STD-461C, CE03
• Compatible with MIL-STD-704E
DC power bus
EMI I
NPUT
F
ILTER
28 V
OLT
I
NPUT
I
NPUT
V
OLTAGE
AND
C
URRENT
Input (V)
28
Current ( A)
10
Size (max.): 3.005 x 1.505 x 0.400 inches (76.33 x 38.23 x 10.16mm)
See Section B8, case U1, for dimensions.
Weight:
110 grams maximum
Screening: Standard, Class H, or Class K (MIL-PRF-38534)
See Section C2 for screening options, see Section A5 for
ordering information.
DESCRIPTION
The SFME28-461™ Series EMI filter modules are specifically
designed to reduce the reflected input ripple current of high
frequency DC/DC converters. SFME28-461 filters minimize electro-
magnetic interference (EMI) for Interpoint’s space applications
converters. These filters are intended for use in 28 volt applications
which must meet MIL-STD-461 levels of conducted emissions. One
filter can be used with multiple converters up to the rated throughput
current of the filter.
Where low noise currents are required to meet CE03 of MIL-STD-
461, a power line filter is needed. The SFME28-461 Series of EMI
power line filters reduces the common mode and differential noise
generated by the converters. SFME28-461 filters reduce input ripple
current by as much as 60 dB at 500 kHz and 55 dB at 1 MHz when
used in conjunction with Interpoint’s DC/DC converters.
The filter must be placed as close as possible to the converter for
optimum performance. The baseplates of the filter and the converter
should be connected with the shortest and widest possible conduc-
tors. For the best connection, mount the filter’s and converter’s
baseplates on or above a small ground plane.
S
CREENING AND
R
EPORTS
The SFME28-461 filter offers three screening options – Standard,
Class H, or Class K. See Section C2, Quality Assurance, pages C2-
7 through C2-9, for descriptions. Detailed reports on product
performance are also available and are listed on page C2-9.
O
PERATION OVER
T
EMPERATURE
All SFME28-461 Series filters are rated for full power operation from
–55°C to +125°C case temperature. Current is derated linearly to
zero at +135°C case temperature.
I
NPUT
R
IPPLE AND
EMI
Switching DC/DC converters naturally generate two noise compo-
nents on the power input line: differential noise and common mode
noise. Input ripple current refers to both of these components.
Differential noise occurs between the positive input and input
common. Most Interpoint converters have an input filter that reduces
differential noise which is sufficient for most applications.
Common mode noise occurs across stray capacitances between
the converter’s power train components and the baseplate (bottom
of the package) of the converter.
I
NSERTION
L
OSS
The maximum dc insertion loss at full load and nominal input voltage
represents a power loss of less than 4%.
P
ACKAGING
SFME28-461filters are sealed in metal hermetic side-leaded pack-
ages.
For more information, contact your Interpoint representative
listed in Section A5.
B1-13
All technical information is believed to be accurate, but no responsibility is assumed
for errors or omissions. Interpoint reserves the right to make changes in products
or specifications without notice. SFME28+461 is a trademark of Interpoint.
Copyright © 1999 Interpoint. All rights reserved.
CRANE [ Crane Aerospace & Electronics. ]
