B5-7
DESCRIPTION
The MSF-461 EMI filter module has been specifically designed to
reduce the input line reflected ripple current of Interpoint's MSR and
DCH Series of DC/DC converters. They are intended for use in
applications where switch-mode DC/DC converters, operating at a
frequency of higher than 50 kHz, must meet MIL-STD-461C levels
of conducted power line noise.
MSF-461 EMI 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, case C3, for dimen-
sions. See Section C2 for screening options.
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 50 dB within the frequency band of 50 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 MSR2812D converter with and without the MSF-
461 filter is shown in Figures 4 and 5.
F
ILTER
O
PERATION
The MSF-461 filters are rated to operate, with no degradation of
performance, over the temperature range of 55C to +85C (as
measured at the baseplate). Above 85C, input voltage and current
must be derated as specified in "Derating" on the following page.
The maximum power dissipation of 0.62 watts (at maximum input
current) represents a power loss of less than 10% at typical input
voltage.
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.
EMI I
NPUT
F
ILTER
28 V
OLT
I
NPUT
MSF EMI FILTER
0.8 AMP
F
EATURES
55C to +85C operation
50 dB minimum attenuation
at 500 kHz
Compliant to MIL-STD-461C, CE03
Overvoltage protection
Size (max.): 1.075 x 1.075 x 0.370 (27.31 x 27.31 x 9.40 mm)
See Section B8, cases C3, for dimensions.
Weight:
15 grams typical, 16 grams maximum
Screening: Standard or ES. See Section C2 for screening
options, see Section A5 for ordering information.
MODEL
MSF-461
0.8 amp
RECOMMENDED OPERATING CONDITIONS
TYPICAL CHARACTERISTICS
DERATING
ABSOLUTE MAXIMUM RATINGS
Input Voltage
0 to 40 VDC continuous
Lead Soldering Temperature (10 sec per lead)
300C
Storage Temperature Range (Case)
55C to +125C
B5-8
MSF EMI FILTER
0.8 AMP
Input Voltage Range
0 to 40 VDC continuous
Case Operating Temperature (Tc)
55C to +85C full power
Electrical Characteristics: 25C Tc, nominal Vin, unless otherwise specified.
EMI I
NPUT
F
ILTERS
Capacitance
6600 pF max, any pin to case
Isolation
100 megohm minimum at 500 V
Any pin to case, except case pin
0.01 F
0.001 F
100
1000 pF
500 V
Positive
Input
Input
Common
Positive
Output
Output
Common
MSF-461
570 H
x4
x2
50
1000 pF
500 V
x2
x2
4.7 F
F
IGURE
1: S
CHEMATIC
MSF-461
PARAMETER
CONDITIONS
MIN TYP MAX
UNITS
INPUT VOLTAGE
CONTINUOUS
0
28
40
VDC
INPUT CLAMPING
55C
38.9
43.2
47.5
VOLTAGE
25C
42.3
47.0
51.7
VDC
85C
44.9
49.9
54.8
INPUT CURRENT
--
--
420
mA DC
NOISE REJECTION
50
--
--
dB
DC RESISTANCE
1
(R
DC
)
TC = 25C
3.00
3.20
3.50
OUTPUT VOLTAGE
2
STEADY STATE
V
OUT
= V
IN
- I
IN
(R
DC
)
VDC
OUTPUT CURRENT
STEADY STATE
--
--
420
A
INTERNAL POWER
DISSIPATION
MAXIMUM CURRENT
--
--
0.62
W
Notes
1. DC resistance measured using four wire technique.
2. Typical applications result in Vout within 5% of Vin.
Input Voltage
Derate linearly from 100% at 85C case to
the 33 VDC at 125C case
DC Input and Output Current
Derate linearly from 100% at 85C case to
150 mA at 125C case.
PIN OUT
Dot on top of cover
indicates pin one.
BOTTOM VIEW
MSF
1 2
4
5
9
6
7
8
3
MSF - 461 / ES
Base Model
MIL-STD-461 reference
Screening
(Standard screening has no designator
in this position.)
B5-9
MODEL NUMBERING KEY
EMI I
NPUT
F
ILTERS
See Section B8, case C3, for dimensions.
Pin
Designation
1, 2
1
Input Common
3, 4
1
Positive Input
5, 6
1
Positive Output
7
Case Ground
8, 9
1
Output Common
F
IGURE
3: P
IN
O
UT
MSF EMI FILTER
0.8 AMP
+Vin
+Vout
Input
Common
Output
Common
Case
R
L
MSF-461
MSR CONVERTER
+Vin
+Vout
Input
Common
Output
Common
Case
+
1, 2
3, 4
5, 6
1, 2
7
4
8, 9
17, 18
12, 13
8, 9
F
IGURE
2: C
ONNECTION
D
IAGRAM
Note
1. Make external connections to
both pins.
B5-10
Typical Performance Curves: 25C Tc , nominal Vin, unless otherwise specified.
EMI I
NPUT
F
ILTERS
MSF EMI FILTER
0.8 AMP
90
70
50
30
.015
.1
1
10
50
10
EMISSION LEVEL (dmA)
FREQUENCY (MHz)
CE03 Limit
90
70
50
30
.015
.1
1
10
50
10
EMISSION LEVEL (dmA)
FREQUENCY (MHz)
CE03 Limit
F
IGURE
4
F
IGURE
5
Narrowband spectrum of an MSR2812D
converter without an EMI filter.
Narrowband spectrum of an MSR2812D converter
with an MSF-461 filter on the input line.
27421-001-DTS Rev A
DQ# 4007
All technical information is believed to be accurate, but no responsibility is
assumed for errors or omissions. Interpoint reserves the right to make changes in
products or specifications without notice. Copyright 1994 - 1999 Interpoint. All
rights reserved.
B8-8
CASE C
C
ASES
CASE C
BOTTOM VIEW
See Figures 9 - 11
for pin configurations.
1.075 max
(27.31)
Materials
Header Case C1
Cold Rolled Steel/Nickel/Gold
Cases C2 and C3
Kovar/Nickel/Tin
Cover Case
C1
Cold Rolled Steel/Nickel
Cases C2 and C3
Kovar/Nickel/Tin
Pins Case
C1
Copper/Nickel/Gold
Cases C2 and C3
Kovar/Nickel/Gold,
matched glass seal
Case dimensions in inches (mm)
Tolerance
0.005 (0.13) for three decimal places
0.01 (0.3) for two decimal places
unless otherwise specified
1.075 max
(27.31)
CAUTION
Heat from reflow or wave soldering may
damage the device. Solder pins
individually with heat application not
exceeding 300
C for 10 seconds per
pin.
Dot on top of case
indicates pin one
0.000
0.132
(3.35)
0.932
(23.67)
0.000
0.132 (3.35)
8
7
6
5
4
3
2
1
0.332 (8.43)
0.532 (13.51)
0.732 (18.59)
0.932 (23.67)
0.025
(0.64)
dia.
0.000
0.270 max.
(6.86)
MSA Series: Screening Standard, ES, or 883
SMSA Series: Screening Space Standard, H, or K
BOTTOM VIEW CASE C1
0.205
0.010
(5.21
0.25)
0.000
0.270 max.
(6.86)
0.205
0.010
(5.21
0.25)
Projection Weld
Seam Seal
Squared corner and dot on
top of case indicate pin one.
1 2
9
10
17
18
0.018
0.002 dia.
(0.46
0.05)
0.350 (8.89)
0.000
Pins equally
spaced
Marker bead
on pin 18
MSR Series: Screening Standard or ES
HR40 Series: No screening options
BOTTOM VIEW CASE C2
0.205
0.010
(5.21
0.25)
Dot on top of case
indicates pin one
0.100 (2.54)
0.370 max.
(9.40)
0.800 (20.32)
0.800 (20.32
1 2
4
5
9
0.018
0.002 dia.
(0.46
0.05)
6
7
MSF EMI Filter: Screening Standard or ES
8
BOTTOM VIEW CASE C3
0.350 (8.89)
0.000
0.370 max.
(9.40)
0.205
0.010
(5.21
0.25)
Dot on top of case
indicates pin one
0.100 (2.54)
0.800
(20.32)
0.800 (20.32
0.600
(15.24)
0.300
(7.62)
3
0.000
0.365 max.
(9.27)
0.205
0.010
(5.21
0.25)
Seam Seal
F
IGURE
9:
C
ASE
C1
F
IGURE
10:
C
ASE
C2
F
IGURE
11:
C
ASE
C3
F
IGURE
8: C
ASE
C
M
AXIMUM
D
IMENSIONS
Note: Although every effort has been
made to render the case drawings at
actual size, variations in the printing
process may cause some distortion.
Please refer to the numerical dimen-
sions for accuracy.
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