Crane Aerospace & Electronics Power Solutions
sFMc28-461 eMi input Filters
28 Volt input – 2.7 AMp
Features
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•
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•
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Fully qualified to Class H or K
Passive components used for maximum tolerance
in space environments
-55°C to +125°C operation
Nominal 28 V input, 0 V to 50 V operation
Up to 2.7 A throughput current
60 dB attenuation typical at 500KHz
Compliant to MIL-STD-461C CE-03
Compatible with MIL-STD-704 A-E 28 VDC power bus
I
nput
V
oltage
and
C
urrent
Input (V)
28
Current (A)
2.7
Description
The SFMC28-461™ EMI filters provide an off-the-shelf filtering
solution compliant to MIL-PRF-38534, Class H or Class K,
for use in your space system. SFMC28-461 filters reduce
the input line reflected ripple current of our switching DC/DC
converters. Use an SFMC28-461 filter with our SMTR, SMHF
and SMSA series of DC/DC converters to meet MIL-STD-461C
levels of conducted emission (CE01, CE03). The SFMC filters
are designed exclusively with passive components providing
maximum tolerance for space environments.
Derating according to the requirements of MIL-STD-975 assures
dependable performance in the harsh environments of space.
Compliance to MIL-STD-975 derating is achieved at or below
case operating temperatures of 90°C.
All SFMC28-461 filters are built to the same assembly drawing
regardless of environmental screening or radiation tolerance
level. Filters designated level OO, indicating standard environ-
mental screening, are electrically comparable to filters designated
level KH, the highest environmental screening level. This ensures
consistency between your prototype or test system using level
OO filters and your flight system using filters with higher levels of
environmental screening and radiation tolerance. Element evalu-
ation (screening at the component level) of Class H or Class K
filters ensures even greater reliability. Refer to Table 1, 2, and 3
for more information.
S
creening
The SFMC28-461 EMI filters offer environmental screening
levels to Space Prototype (O), Class H, or Class K requirements.
Radiation tolerant to Radiation Hardness Assurance (RHA) levels
of “-” (O) or “H”, per MIL-STD-38534. Interpoint model numbers
use an “O” in the RHA designator position to indicate the “-”
(dash) Radiation Hardness Assurance level of MIL-PRF-38534,
which is defined as “no RHA”. See “Class H and K,
MIL-PRF-38534 Screening” tables for more information.
o
perating
t
emperature
r
ipple
r
eduction
The SFMC28-461 EMI filter, when used with Interpoint’s
converters, reduces reflected input ripple current by a minimum
of 55 dB at 500 kHz and 60 dB at 1 MHz. The filter and converter
combination performance exceeds the CEO3 requirements of
MIL-STD-461C.
The filter operates at full load over the temperature range of
-55°C to +125°C case. Above +125°C, the current must be
derated as specified on page two.
p
ackaging For
S
pace
i
nSertion
l
oSS
F
ilter
d
eSign
The maximum DC insertion loss for the SFMC28-461 filter (at a
load of 22 watts) represents a power loss of less than 2%.
SFMC28-461 filters incorporate thick-film hybrid technology and
use only high quality ceramic capacitors for reliable high temper-
ature operation.
SFMC28-461 EMI filters are encased in high-reliability, hermeti-
cally-sealed metal packages and weigh just 48 grams. A small
footprint of 2.110 Inches (53.59 mm) by 1.115 inches (28.32 mm)
by 0.400 inches (10.16 mm) minimizes the board area needed for
the filter. Cover marking inks are NASA approved to Total Mass
Loss (TML) and Collected Volatile Condensable Material (CVCM)
outgassing requirements for operation in space environments.
Crane Aerospace & Electronics
Electronics Group (Interpoint Brand)
PO Box 97005 • Redmond WA 98073-9705
425.882.3100 • electronics@craneae.com
www.craneae.com
Page 1 of 11
Rev D - 20070404
CRANE [ Crane Aerospace & Electronics. ]
