Description

The FMD28 Series™ EMI filters are specifically designed to

reduce the reflected input ripple current of Interpoint’s high

frequency DC/DC converters. FMD filters minimize electro-

magnetic interference (EMI) for the MOR, MFL, MTR, MHV,

MHF+, MHF, MTO and MHE Series of converters. These filters

are intended for use in 28 volt applications which must meet

MIL-STD-461C CE03 levels of conducted emissions. One filter

can be used with multiple converters up to the rated output

current of the filter.

Switching DC/DC converters naturally generate two noise

components 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 many appli-

cations. Common mode noise occurs across stray capacitances

between the converter’s power train components and the base-

plate (bottom of the package) of the converter.

Where low noise currents are required to meet CE03 of

MIL-STD-461C a power line filters reduces the common mode

and differential noise generated by the converters. FMD28-

461 filters reduce input ripple current by as much as 50 dB

at 500 kHz when used in conjunction with Interpoint’s DC/DC

converters.

Place the filter 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

conductors.

A transient of 100 V for up to 100 ms with a 0.5 ohm source

impedance will not damage the filter.

The FMD28-461 Series filters are rated for full power opera-

tion from -55°C to +125°C case temperature. Current is derated

linearly to zero at +135°C case temperature.

The maximum dc insertion loss at full load and nominal input

voltage represents a power loss of less than 1.3%.

FMD28-461 filters are sealed in metal hermetic, down-leaded

packages (case J4). Also available in a side-leaded package

(case U).

Features

attenuation to 50 dB at 500 kHz

Operating temperature -55° to +125°C

•

Nominal 28 V input, 0 to 50 V operation

•

Transient rating to 100 V for 100 ms

•

Up to 7 A throughput current

•

Compliant to MIL-STD-461C, CE03

•

Compatible with MIL-STD-704 A-E 28 VDC power bus

•

Crane Aerospace & Electronics Power Solutions

FMD28-461 eMi input Filters

Crane Aerospace & Electronics

Electronics Group (Interpoint Brand)

POBox97005•RedmondWA98073-9705

425.882.3100•power@crane-eg.com

www.interpoint.com

Page 1 of 8

FMD28 Rev C - 20100226

28 Volt input – 7 aMp