MODELS

AND

B5-3

Input (V)

0 - 40

0 - 40

0 - 40

Current ( A)

1.75

3.8

5.0

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.

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.

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.

The case of the filter must be connected to the case of the converter

through a low impedance connection to minimize EMI.

FM-461, FMA-461

AND FMB-461

EMI FILTERS

1.75 TO 5 AMP

• –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

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.