Datasheet
VEMI85AA-HGK
www.vishay.com
Vishay Semiconductors
Rev. 1.8, 09-Jan-2019
2
Document Number: 81386
For technical questions, contact: EMIFilter@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
APPLICATION NOTE
With the VEMI85AA-HGK 8 different signal or data lines can be filtered and clamped to ground. Due to the different clamping
levels in forward and reverse direction the clamping behaviour is Bidirectional and Asymmetric (BiAs).
The 8 independent EMI-filter are placed between
pin 1 and pin 16,
pin 2 and pin 15,
pin 3 and pin 14,
pin 4 and pin 13,
pin 5 and pin 12,
pin 6 and pin 11,
pin 7 and pin 10 and
pin 8 and pin 9.
They all are connected to a common ground pin 17 on the backside of the package.
The circuit diagram of one EMI-filter-channel shows two identical Z-diodes at the input to ground and the output to ground.
These Z-diodes are characterized by the breakthrough voltage level (V
BR
) and the diode capacitance (C
D
). Below the
breakthrough voltage level the Z-diodes can be considered as capacitors. Together with these capacitors and the line
resistance R
S
between input and output the device works as a low pass filter. Low frequency signals (f < f
3dB
) pass the filter
while high frequency signals (f > f
3dB
) will be shorted to ground through the diode capacitances C
D
.
Each filter is symmetrical so that both ports can be used as input or output.
L1
IN
L1
OUT
L3
IN
L3
OUT
L2
IN
L2
OUT
L4
IN
L4
OUT
L5
IN
L5
OUT
L6
IN
L6
OUT
L7
IN
L7
OUT
L8
IN
L8
OUT
20389
1
2
3
4
17
5
6
7
8
9
10
11
12
13
14
15
16
R
S
Out
(
pin 9, 10, 11, 12, 13, 14, 15, 16)
In
(pin 1, 2, 3, 4, 5, 6, 7, 8)
GND
(pin 17)
C
D
20390
C
D
C
D