F
EATURES
• –55°C to +85°C operation
• 0 to 40 VDC volt input
• Up to 40 dB attenuation
110 kHz to 50 MHz
• Transient suppression
• Compliant to
MIL-STD-461C, CE03
EMI I
NPUT
F
ILTERS
28 V
OLT
I
NPUT
FM-461, FMA-461
AND FMB-461
EMI FILTERS
1.75 TO 5 AMP
MODELS
I
NPUT
V
OLTAGE
AND
C
URRENT
Input (V)
0 - 40
0 - 40
0 - 40
Current ( A)
1.75
3.8
5.0
Size (max.): Non-flanged case H3 or H5
2.125 x 1.125 x 0.495* inches (53.98 x 28.58 x 12.57* mm)
Flanged case K4 or K6
2.910 x 1.125 x 0.495* inches (73.91 x 28.58 x 12.57* mm)
See Section B8, cases H3, H5, K4, and K6, for dimensions.
*Height varies depending on model.
Weight:
Maximum – FM-461 38 grams, FMA-461 42 grams, FMB-461 43 grams
Screening: Standard or ES. See Section C2 for screening options, see Section A5
for ordering information.
DESCRIPTION
The FM-461, FMA-461, and FMB-461 EMI filter modules have been
specifically designed to reduce the input line reflected ripple current
of Interpoint’s MTO, MTW, MHE, MLP, and MFW Series of DC/DC
converters. They are intended for use in applications of high
frequency ( 100 kHz) switch-mode DC/DC converters which must
meet MIL-STD-461C levels of conducted power line noise.
These filters are built using thick-film hybrid technology and are
sealed in metal packages for military, aerospace, and other high-
reliability applications. See Section B8, cases H3, H5, K4, and K6
for dimensions. See Section C2 for screening options.
F
ILTER
O
PERATION
A fast-reacting (1 picosecond) transient suppressor clamps the input
voltage at approximately 47 V, protecting the DC/DC converter from
line induced transients.
The filters are rated to operate, with no degradation of performance,
over the temperature range of –55°C to +85°C (as measured at the
baseplate). Above 85°C, input voltage and current must be derated
as specified in “Derating” on the following page. The maximum
power dissipation of the filters at maximum input current represents
a power loss of less than 3% at typical input voltage.
MIL-STD N
OISE
M
ANAGEMENT
When used in conjunction with Interpoint’s DC/DC converters (see
connection diagram, Figure 2), the input ripple current will be
reduced by 40 dB within the frequency band of 100 kHz to 50 MHz.
This gives the filter/converter combination a performance which
exceeds the CE03 test limit of MIL-STD-461C. The CE03 perform-
ance of a model MHE2805S converter with and without the FM-461
filter is shown in Figures 6 and 7.
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.
B5-3
INTERPOINT [ INTERPOINT CORPORATION COMPANY ]
