MAX4357ECD+ Maxim Integrated Products, MAX4357ECD+ Datasheet - Page 36

• Manufacturer Part Number: MAX4357ECD+
• Description: Analog & Digital Crosspoint ICs 32 x 16 Nonblocking Video Crosspoint Swi
• Manufacturer: Maxim Integrated Products

Specifications of MAX4357ECD+

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

32 x 16 Nonblocking Video Crosspoint Switch
with I/O Buffers
Figure 6. 128 x 32 Nonblocking Matrix Using 32 x 16
Crosspoint Devices
36
Table 5. Output Selection Programming
(96–127)
INPUTS
INPUTS
INPUTS
(64–95)
INPUTS
(32–63)
(0–31)
______________________________________________________________________________________
B3 (MSB)
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
32
IN
32
IN
32
IN
32
IN
MAX4357
MAX4357
MAX4357
MAX4357
OUT
OUT
OUT
OUT
OUTPUTS (0–15)
16
16
16
16
OUTPUT ADDRESS BIT
32
IN
32
IN
32
IN
32
IN
B2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
MAX4357
MAX4357
MAX4357
MAX4357
OUT
OUT
OUT
OUT
OUTPUTS (16–31)
16
16
16
16
B1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
A single R-C does not affect the performance at video
frequencies, but in a very large system there may be
many R-Cs cascaded in series. The cumulative effect is
a slight rolling off of the high frequencies causing a
"softening" of the picture. There are two solutions to
achieve higher performance. One way is to design the
PC board traces associated with the outputs such that
they exhibit some inductance. By routing the traces in a
repeating "S" configuration, the traces that are nearest
each other exhibit a mutual inductance increasing the
total inductance. This series inductance causes the
amplitude response to increase or peak at higher fre-
quencies, offsetting the rolloff from the parasitic capaci-
tance. Another solution is to add a small-value inductor
to the output.
Improper signal routing causes performance problems.
The MAX4357 has a typical crosstalk rejection of
-62dB at 6MHz. A bad PC board layout degrades the
crosstalk rejection by 20dB or more. To achieve the
best crosstalk performance:
1. Place ground isolation between long critical signal
PC board trace runs. These traces act as a shield to
potential interfering signals. Crosstalk can be
degraded from parallel traces as well as directly
above and below on adjoining PC board layers.
Crosstalk and Board Routing Issues
B0 (LSB)
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
SELECTED OUTPUT
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9