ZXFV302EV Datasheet, PDF (1/3 Pages) Zetex Semiconductors – 4:1 CHANNEL VIDEO MULTIPLEXER EVALUATION BOARD

ZXFV302EV
4:1 CHANNEL VIDEO MULTIPLEXER EVALUATION BOARD
Evaluation board description
The wide bandwidth of the ZXFV302 4:1 channel video
multiplexer necessitates some care in the layout of the
printed circuit. For this reason Zetex has made
available an Evaluation Board.
The Evaluation Board layout serves as a useful
example for many applications, showing a practical
implementation of the advice given below.
The ZXFV302EV can also be used to evaluate the
ZXFV301 4:1 channel multiplexer. The ZXFV301 and
ZXFV302 devices have very similar ac performance,
with the only difference being in the active channel
selection.
Figures 1, 2 and 3 show the schematic and copper
layout of a double-sided printed circuit board suitable
for evaluation of the device in the laboratory.
BNC connector sockets allow connection to test
instruments via 50⍀ cables. The output circuit includes
a resistor matching circuit to present a load of 150⍀ to
the amplifier (equivalent to a 75⍀ back-terminated
video line) and simultaneously provide 50⍀ output
impedance.
The attenuation of this matching circuit is 15.45 dB. As
the multiplexer is internally configured for a voltage
gain of 1, the overall gain from input to output is
-15.45dB.
ISSUE 1 - SEPTEMBER 2004
Figure 1 Circuit schematic
1
SEMICONDUCTORS