F
EATURES
• –55°C to +125°C operation
• 50 dB minimum 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
FMH EMI FILTER
1.5 AMP
MODEL
FMH-461
1.5 amp
Size (max.): Non-flanged, case E3
1.460 x 1.130 x 0.330 (37.08 x 28.70 x 8.38 mm)
Flanged, case G3
2.005 x 1.130 x 0.330 inches (50.93 x 28.70 x 8.38 mm)
See Section B8, cases E3 and G3, for dimensions.
Weight:
22 grams typical, 28 grams maximum
Screening: Standard, ES, or 883 (Class H). See Section C2 for screening
options, see Section A5 for ordering information.
DESCRIPTION
Interpoint specifically designed the FMH-461™ EMI filter to reduce
the input line reflected ripple current of the following high frequency
DC/DC converters: MHD, MHF, MHF+, MHV, MSA
1
, and MTR
series converters. It will also reduce EMI for several of Interpoint’s
lower frequency converters: MHE/MLP, MHL, MTO, and MTW
series. The FMH-461 filter is ideal for use in applications which must
meet MIL-STD-461C levels of conducted and radiated emissions.
Throughput current is 1.5 amps. At 16 VDC input (low line), the filter
provides 24 watts of throughput power.
F
ILTER
O
PERATION
FMH-461 filters are rated for full power operation from –55°C to
+125°C baseplate temperature. Operation is offered up to the
absolute maximum of +135°C with derating as defined in
“Recommended Operating Conditions” on the following page. The
maximum DC insertion loss at full load and nominal input voltage
(28 VDC) represents a power loss of less than 2%.
L
AYOUT
R
EQUIREMENTS
The case of the filter must be connected to the case of the converter
through a low impedance connection to minimize EMI.
MIL-STD N
OISE
M
ANAGEMENT
When used in conjunction with Interpoint converters, the FMH-461
EMI filter reduces input ripple current by 35 dB or greater at 200 kHz
and by at least 50 dB at 500 kHz (see Figures 5 and 6 and electrical
characteristics table). This attenuation gives the converter/filter
combination performance which exceeds MIL-STD-461C’s CE03
test.
1. MSA models may require an inductor in series with the MSA’s positive input.
2 µH is the suggested value.
B3-17
CRANE [ Crane Aerospace & Electronics. ]
