Crane Aerospace & Electronics Power Solutions
FM-704a eMi input Filter and transient suppression Module
28 Volt input – 40 Watt
Features
active transient suppression
undervoltage lockout
• -55°C to +125°C operation
• 16 to 40 VDC input
• Inhibit function
• Up to 60 dB attenuation at 500 kHz.
• Compliant to MIL-STD-461A-F
MoDEL
FM-704A
40 WATT
Description
The Interpoint™ FM-704A™ EMI Filter and Transient
Suppression Module combines EMI filtering and transient
protection to handle the demanding requirements of military,
aerospace and industrial applications. As an EMI filter the
FM-704A filter reduces the reflected ripple current from DC/DC
switching converters. As a protection module, it suppresses input
transients on the power bus to protect the converter and other
downstream components.
I
NTerNaL
p
ower
D
ISSIpaTIoN
To keep internal power dissipation to safe operating levels, the
input current should never exceed 2.5 amps at 16 Vin or 1.0 amp
at 40 Vin. When the FM-704A filter is used with PWM (Pulse
Width Modulated) converters,
Iline
will vary as Power / Vline
and 2.5 amps maximum at 16 Vin will reduce to approximately 1
amp maximum at 40 Vin. The maximum value allowed may be
less than 1 amp as determined by line transients and the safe
operating area of Figure 9.
Figure 9 illustrates the maximum allowed internal dissipation for
the FM-704A filter. To calculate watts dissipated, subtract 40
volts from the transient (VT) to determine the maximum voltage
across the filter and multiply the result by the current (the filter’s
output power, Pout divided by 40):
W = (VT - 40) x Pout /40
For example, with 20 watts output and a transient of 400 volts:
W = (400 - 40) x 20/40 = 180
The curve of Figure 9 shows that 180 W can be dissipated for up
to 4 milliseconds.
MIL-STD N
oISe
M
aNageMeNT
When used in conjunction with Interpoint converters, the
FM-704A EMI filter reduces reflected input ripple current by a
minimum of 60 dB at 500 kHz and 55 dB at 1 MHz (see Electrical
Characteristics table on page 5 and Figures on page 6). This
attenuation gives the converter/filter combination performance
exceeding MIL-STD-461C’s CE03 test. Although the FM-704A
filter effectively attenuates the ripple generated by switching
converters, it will not suppress RF applied to its input terminals.
T
eMperaTure
o
peraTIoN
FM-704A filters are rated to operate from -55°C to +125°C
baseplate temperature. To meet MIL-STD-1275A and MIL-STD-
704A requirements, derate output power linearly from 40 watts at
105°C to 20 watts at 125°C. See Figure 9.
F
eaTureS
p
roTecTIoN
The inhibit function allows the FM-704A filter to be used as a
high-side switch. When the inhibit terminal (pin 6) is left open or
pulled high, the FM-704A filter is enabled. When the terminal is
grounded, the filter shuts off output power.
A soft start function helps reduce inrush current and start-up
overshoot when the filter is initially powered or when it is
released from the inhibit mode.
An undervoltage lockout feature shuts off output power when
input voltage falls below a specified level. Refer to Figure 8 for
more information.
To provide protection for itself and converters, the FM-704A filter
blocks transients as required by the following standards:
MIL-STD-704A
Panavia SP-P-90001
MIL-STD-461A through F British Standard BS3G100
MIL-STD-1275
Civil Aircraft D0160B
Refer to the Electrical Characteristics table on page 5 for more
information.
Reverse polarity spikes of up to 100 V will not damage the filter,
however the spikes will not be blocked by the filter.
Crane Aerospace & Electronics
Power Solutions - Interpoint Products
10301 Willows Road NE, Redmond, WA 98052
+1.425.882.3100 • power@crane-eg.com
www.craneae.com/interpoint
L
ayouT
r
equIreMeNTS
To minimize EMI, common mode noise, the case of the filter
must be connected to the case of the converter through a low
impedance connection.
Page 1 of 9
FM-704A Rev C - 2011.11.07
Crane Aerospace & Electronics Power Solutions
FM-704a eMi input Filter and transient suppression Module
28 Volt input – 40 Watt
Operating COnditiOns and CharaCteristiCs
input Voltage range
• 16 to 40 VDC continuous for 40 W load
inhibit
lead soldering temperature (10 sec per pin)
• 300°C
storage temperature range (case)
• -65°C to +150°C
• Active low (output disabled)
‣
Active low 0.8 V max
‣
Inhibit pin will source 0.6 mA max.
• Active high (output enabled)
‣
open collector
‣
open pin voltage 5.5 V max.
case operating temperature (t
c
)
• -55°C to +125°C full power
isolation (t
c
= 25°c)
• 100 megohm minimum at 500 V
• Any pin to case, except case pin
undervoltage lockout
• 7 VDC min, 15 VDC max
capacitance
• 0.017 µF max, any pin to case
Derating output power/current
• Linearly from 40 W at 105°C to 20 W at 125°C to meet
MIL-STD-1275A (AT) and MIL-STD-704A
meChaniCal and envirOnmental
size (maximum)
• 2.910 x 1.125 x 0.400 inches (73.91 x 28.58 x 10.16 mm)
• See case K1 for dimensions.
Weight (maximum)
• 40 grams typical
screening
• Standard, ES, or 883 (Class H). See Screening Tables 1 and 2
for more information.
Positive
Input
25
3300
pF
Input
Common
Inhibit
Oscillator
390
H
3.6
H
3.6
H
3300 pF
500V
Positive
Output
0.068
F
6
F
6
F
Case
6600 pF
500V
3300 pF / 500V
15
Output
Common
FM-704A
The case ground connection between the filter and the converter should be as low
an impedance as possible to minimize EMI. Direct contact of the baseplate to
chassis ground provides the lowest impedance.
F
Igure
1: S
cheMaTIc
– T
ypIcaL
V
aLueS
www.craneae.com/interpoint
Page 2 of 9
FM-704A Rev C - 2011.11.07
Crane Aerospace & Electronics Power Solutions
FM-704a eMi input Filter and transient suppression Module
28 Volt input – 40 Watt
pins not in use
pin
2
4
5
6
1
3
pin out
Positive output
output Common
Input Common
Inhibit
Case Ground
Positive Input
Designation
inhibit
Leave unconnected
Dot on top of package indicates pin one
1
6
2
5
See case K1 for dimensions.
BOTTOM VIEW
FM-704A
3
4
F
Igure
2: p
IN
o
uT
www.craneae.com/interpoint
Page 3 of 9
FM-704A Rev C - 2011.11.07
Crane Aerospace & Electronics Power Solutions
FM-704a eMi input Filter and transient suppression Module
28 Volt input – 40 Watt
MoDel nuMbering key
Base Model
FM - 704A /
883
94028-01HXC
DLA D
rAwing
(5915)
Dla nuMbers
FM-704A S
iMiLAr
P
Art
FM-704A/883
MIL-STD-704A Reference
Screening
(Standard screening has no designator
in this position.)
For exact specifications for a DLA product, refer to the
DLA drawing. DLA drawings can be downloaded from:
http://www.landandmaritime.dla.mil/Programs/MilSpec/
default.aspx
enter one oPtion FroM eAch cAtegory
in the ForM beLow
.
t
o DeterMine the MoDeL nuMber
base Model and
input Voltage
MoDel nuMber options
1
category
options
Fill in For
MoDel #
screening
2
standard (leave blank)
FM-704a
es
883 (class H)
FM-704a
__________
Notes:
1. See Model Numbering Key above for an example of a model number.
2. Screening: For standard screening leave the screening option blank. For other
screening options, insert the desired screening level. For more information see
Screening Table 1.
/
www.craneae.com/interpoint
Page 4 of 9
FM-704A Rev C - 2011.11.07
Crane Aerospace & Electronics Power Solutions
FM-704a eMi input Filter and transient suppression Module
28 Volt input – 40 Watt
Electrical Characteristics: -55 to +125°C T
C
, nominal Vin, unless otherwise specified.
FM-704A
paraMeTer
INpuT VoLTage
coNDITIoNS
No LoaD
40 W LoAD
UNDERVoLTAGE LoCKoUT
INpuT curreNT
16 V
IN
1
40 V
IN
1
MIN
16
1
7
–
–
–
–
40
–
–
60
55
–
0
TYP
28
28
–
–
–
–
–
–
–
–
–
–
–
MAX
40
1
15
2.5
1.0
5
2
50
50
50
–
–
0.45
A
mA
V
oUT
V
oUT
dB
ohms
VDC
A
40
uNITS
VDC
No LoAD
INpuT Surge
INpuT SpIKe
DIFFereNTIaL MoDe
NoISe reJecTIoN
Dc reSISTaNce (r
Dc
)
1
ouTpuT VoLTage
ouTpuT curreNT
1
INTerNaL power
D
I
SSIpaTIoN
1
peaK
40 W, 100 V, 0.5 Ω Z
S
, 60 ms
2
40 W, 600 V, 50 Ω Z
S
, 10 ms
1
,
4
500 kHz
1 MHz
STeaDy STaTe
INhIBITeD
16 V
IN
40 V
IN
T
c
= 105°c
T
c
= 25°c
40 W, 400 V, 0.5 Ω Z
S
, 5 ms
3
INHIBITED
V
oUT
= V
IN
- I
IN
(R
DC
)
–
–
1
–
–
–
–
–
–
8.58
–
–
–
–
–
–
2.5
1.0
1000
500
30
15
16.5
coNTINuouS ( >
Sec
)
capacITaNce
T
c
= 105°c
T
c
= 125°c
T
c
= 125°c
W
aNy pIN To caSe, T
c
= 25°c
nF
Notes
1. guaranteed by design, not tested.
2. Meets MIL-STD-1275A (AT) Surge and Figure 8 and 9 of
MIL-STD-704A. For these standards derate output power
linearly from 40 W at 105°C to 20 W at 125°C.
3. Meets Panavia SP-P-90001, British Standard BS3G100
and Civil Aircraft D0160 Standards.
4. Meets MIL-STD-461C 1.2 CS06 limits.
www.craneae.com/interpoint
Page 5 of 9
FM-704A Rev C - 2011.11.07
电源技术
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
