B1-16
STF28-461
EMI FILTER
0.8 AMP
EMI I
NPUT
F
ILTER
28 V
OLT
I
NPUT
DESCRIPTION
The STF28-461TM EMI filter module has been designed as a
companion for Interpoint SMSA flyback power converters. Multiple
SMSA power converters can be operated from a single filter
provided the total power line current does not exceed the filter
maximum rating. The STF filter will reduce the SMSA's power line
reflected ripple current to within the limit of MIL-STD-461C, Method
CE03, as shown in the example of Figures 4 and 5.
The STF filter is fabricated using thick film hybrid technology and is
sealed in a metal package for space, military, aerospace and other
applications requiring EMI suppression.
S
CREENING AND
R
EPORTS
The STF28-461 filter offers three screening options Standard,
Class H, or Class K. See Section C2, Quality Assurance, pages C2-
7 through C2-9, for descriptions. Detailed reports on product
performance are also available and are listed on page C2-9.
O
PERATION
The SMSA power converter has an internal capacitor across its
input power terminals. When the SMSA and STF filters are used
together, this capacitor becomes part of the filter and forms its final
LC output section.
The STF filter provides both differential and common mode rejection
bringing DC/DC converters into compliance with MIL-STD-461C
CE03. It is designed to be used with the SMSA, SMHF, and MCH
Series of converters. The STF filter can be used with multiple
converters up to the rated current of the filter.
For more information, contact your Interpoint representative
listed in Section A5.
F
EATURES
Fully qualified to Class H or K
Passive components for
maximum tolerance in space
environments
55 to +125C operation
28 volt input
Up to 0.8 amps throughput current
50 dB minimum attenuation
at 500 kHz
Compliant to MIL-STD-461C, CE03
Compatible with MIL-STD-704E
DC power bus
Size (max.): 0.975 x 0.800 x 0.270 (24.77 x 20.32 x 6.86 mm)
See Section B8, cases A1, for dimensions.
Weight:
10.3 grams typical, 11.5 grams maximum
Screening: Standard, Class H, or Class K (MIL-PRF-38534)
See Section C2 for screening options, see
Section A5 for ordering information.
MODEL
STF28-461
0.8 amp
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. STF28-461 is a trademark of Interpoint.
Copyright 1999 Interpoint. All rights reserved.
B8-6
CASE A
C
ASES
CASE A
BOTTOM VIEW
See Figures 2 - 4
for pin configurations.
Dot on top of case
indicates pin one.
0.975 max
(24.77)
0.800 max
(20.32)
Materials
Header
Kovar/Nickel/Gold
(Case A3, Kovar/Nickel)
Cover Kovar/Nickel
Pins 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
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.
0.000
0.097
(2.46)
0.697
(17.70
Squared corner and dot on
top of case indicate pin one.
0.397
(10.08)
0.000
0.135 (3.43)
0.835 (21.21)
0.270 max
(6.98)
0.000
0.735 (18.67)
Projection Weld
Seam Seal
FMSA EMI Filter: Screening Standard, ES, or 883
STF EMI Filter: Screening Space Standard, H, or K
1
3
8
4
7
2
6 5
BOTTOM VIEW CASE A1
0.270 max
(6.86)
0.000
0.27
0.02
(6.9
0.5)
0.27
0.02
(6.9
0.5)
0.018
0.002 dia.
(0.46
0.05)
0.000
0.097
(2.46)
0.697
(17.70
0.000
0.135 (3.43)
0.835 (21.21)
0.270 max
(6.98)
0.000
1
4
7
5
2
3
6
0.235 (5.97)
0.435
(11.05)
0.535 (13.59)
MCH Series: Screening Standard, ES, or 883
SLH Series: Screening Space Standard, H, or K
BOTTOM VIEW CASE A2
0.270 max
(6.86)
0.000
0.27
0.02
(6.9
0.5)
0.27
0.02
(6.9
0.5)
Projection Weld
Seam Seal
Squared corner and dot on
top of case indicate pin one.
0.018
0.002 dia.
(0.46
0.05)
0.000
0.097
(2.46)
0.697
(17.70
0.000
0.135 (3.43)
0.835 (21.21)
1
8
16
9
2 3
0.235 (5.97)
14
15
DCH Series: Screening Standard or ES
0.335 (8.51)
BOTTOM VIEW CASE A3
0.350 max
(8.89)
0.350 max
(8.89)
0.000
0.27
0.02
(6.9
0.5)
0.018
0.002 dia.
(0.46
0.05)
Projection Weld
Dot on top of case
indicates pin one.
0.000
0.27
0.02
(6.9
0.5)
Seam Seal
F
IGURE
2: C
ASE
A1
F
IGURE
3: C
ASE
A2
F
IGURE
4: C
ASE
A3
F
IGURE
1: C
ASE
A 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 dimensions
for accuracy.
C2-7
QA SCREENING
SPACE PRODUCTS
S
PACE
P
RODUCTS
E
LEMENT
E
VALUATION
S
TANDARD
C
LASS
C
LASS
T
EST
P
ERFORMED
(O)
H
K
(
COMPONENT LEVEL
)
M/S
P
M/S
P
M/S
P
Element Electrical
yes
no
yes
yes
yes
yes
Element Visual
no
no
yes
yes
yes
yes
Internal Visual
no
no
yes
no
yes
no
Temperature Cycling
no
no
no
no
yes
yes
Constant Acceleration
no
no
no
no
yes
yes
Interim Electrical
no
no
no
no
yes
no
Burn-in
no
no
no
no
yes
no
Post Burn-in Electrical
no
no
no
no
yes
no
Steady State Life
no
no
no
no
yes
no
Voltage Conditioning /Aging
no
no
no
no
no
yes
Visual Inspection
no
no
no
no
no
yes
Final Electrical
no
no
yes
yes
yes
yes
Wire Bond Evaluation
*
no
no
yes
yes
yes
yes
SEM
no
no
no
no
yes
no
SLAMTM/C-SAM:
Input capacitors only
no
no
no
yes
no
yes
(Add'l test, not req. by H or K)
Definitions
Element Evaluation: Component testing/screening per MIL-STD-883 as determined by MIL-PRF-38534
SEM: Scanning Electron Microscopy
SLAMTM: Scanning Laser Acoustic Microscopy
C-SAM: C - Mode Scanning Acoustic Microscopy
Notes
M/S
Active components (Microcircuit and Semiconductor Die)
P
Passive components
*
Not applicable to EMI filters that have no wirebonds
SMFLHP Series
SMFL Series
SMHP Series (O&H only)
SMTR Series
SSP Series
SMHF Series
SMSA Series
SLH Series
SLIM Module
SFME120 EMI Filter
SFME28 EMI Filter
SFCS EMI Filter
SFMC EMI Filter
STF EMI Filter
Applies to the following products:
C2-8
QA SCREENING
SPACE PRODUCTS
E
NVIRONMENTAL
S
CREENING
T
EST
P
ERFORMED
S
TANDARD
C
LASS
C
LASS
(
END ITEM LEVEL
)
(O)
H
K
Non-destruct bond pull*
Method 2023
no
no
yes
Pre-cap inspection
Method 2017, 2032
yes
yes
yes
Temperature cycle
Method 1010, Cond. C
yes
yes
yes
Constant acceleration
Method 2001, 3000 g
yes
yes
yes
PIND Test
Method 2020, Cond. B
no
no
yes
Radiography
Method 2012
no
no
yes
Pre burn-in test
yes
yes
yes
Burn-in, Method 1015, 125C
96 hours
yes
no
no
160 hours
no
yes
no
2 x 160 hour (includes mid BI test)
no
no
yes
Final electrical test
MIL-PRF-38534, Group A
yes
yes
yes
Hermeticity test
Fine Leak,
Method 1014, Cond. A
yes
yes
yes
Gross Leak,
Method 1014, Cond. C
yes
yes
yes
Final visual inspection
Method 2009
yes
yes
yes
Test methods are referenced to MIL-STD-883 as determined by MIL-PRF-38534.
Note
* Not applicable to EMI filters that have no wirebonds.
SMFLHP Series
SMFL Series
SMHP Series (O&H only)
SMTR Series
SSP Series
SMHF Series
SMSA Series
SLH Series
SLIM Module
SFME120 EMI Filter
SFME28 EMI Filter
SFCS EMI Filter
SFMC EMI Filter
STF EMI Filter
Applies to the following products:
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