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Filter Plate Filter Selection
EMI Filter Performance
The electrical characteristics table and insertion loss graphs
indicate the performance of feedthrough capacitors and Pi type
filters. Utilize this information to specify the EMI filtering
components included in your filter plate.
Custom Filtering
APITech filter plates are engineered to accommodate selective
line filtering. Several different types of filters may be specified in
a single, easy to install filter plate, allowing you to facilitate a
wide range of filtering requirements.
For select line filtering, provide a sketch indicating the filters and
positions required. The example below represents a 10-pin, 2-
row plate with six 1000 pF feedthrough capacitors and four 1700
pF Pi type filters.
F
F F
F
F
F
R
R
R
R
10
1
6
5
Part Number
Based on front
view of plate
Filter
Designation
Filter
Circuits
Capacitance
3 dB Max Cut-
off Frequency
(MHz)*
Working
Voltage DC -
55°C to
+125°C
Minimum Insertion Loss – Decibels (dB)
50 ohm system per MIL-STD-220 (no load)
Value Tolerance
5
MHz
10
MHz
20
MHz
50
MHz
100
MHz
200
MHz
500
MHz
1
GHz
A C 68pF ±20% 77 100V - - - - - 3 10 16
B C 100pF ±20% 53 100V - - - - 1 6 14 19
C C 135pF +100/-0% 23 100V - - - 1 5 10 16 20
D C 470pF ±20% 11 100V - - 2 7 13 19 25 27
E C 820pF ±20% 6 100V - 2 6 12 18 24 30 33
F C 1000pF ±20% 5 100V - 3 7 14 20 26 32 35
G C 1500pF ±20% 3.5 100V 1 4 10 16 22 29 36 37
H C
2500pF +100/-0% 1.3 100V 5 11 17 23 29 35 38 40
I C 4000pF +100/-0% 0.8 100V 9 15 21 27 34 38 42 46
J Insulated 10pF Max. 635 100V - - - - - - - -
K
Grounded
Insert
- - - - - - - -
L Pi 68pF ±20% 65 100V - - - - 1 6 17 23
M Pi 100pF ±20% 46 100V - - - - 2 9 22 28
N Pi 135pF +100/-0% 25 100V - - - 1 6 17 26 34
O Pi 470pF ±20% 11 100V - - - 9 18 22 36 43
P Pi 820pF ±20% 6 100V - - 4 13 23 31 45 52
Q Pi 1000pF ±20% 5 100V - 2 7 16
24 36 51 59
R Pi 1700pF +100/-0% 1.9 100V 1 6 14 28 35 49 64 69
S Pi 2500pF +100/-0% 1.3 50V 4 9 16 28 41 54 70 70
T Pi 5000pF +100/-0% 0.7 100V 9 15 28 41 53 66 70 70
* 3dB cut-off frequency calculated at the maximum capacitance.
** For high-density centers (2mm) only C style filters are available, to maximum of 4000pF
The above curves represent the application of proper grounding fundamentals.
Frequency
0.1MHz
1MHz
10MHz
100MHz
1GHz
10GHz
C-Style Capacitor
A
B
C
D
E
F
G
H
I
0.1MHz
1MHz
10MHz
100MHz
1GHz
10GHz
Pi Capacitor
L
T
S
R
Q
N
M
O
P
Frequency
Insertion Loss (dB)
100
80
60
40
20
0
100
80
60
40
20
0
Insertion Loss (dB)
Typical Insertion Loss