AD8196 Analog Devices, AD8196 Datasheet - Page 18

• Manufacturer Part Number: AD8196
• Description: 2:1 HDMI/DVI Switch with Equalization
• Manufacturer: Analog Devices

AD8196
APPLICATION NOTES
The AD8196 is an HDMI/DVI switch featuring equalized
TMDS inputs and pre-emphasized TMDS outputs. It is in-
tended for use as a 2:1 switch in systems with long cable runs
on both the input and/or the output, and is fully HDMI 1.3
receive compliant.
PINOUT
The AD8196 was designed to have an HDMI/DVI receiver
pinout at its input and a transmitter pinout at its output. This
makes the AD8196 ideal for use in AVR-type applications
where a designer routes both the inputs and the outputs directly
to HDMI/DVI connectors as shown in Figure 31. When the
AD8196 is used in receiver-type applications, it is necessary to
change the ordering of the output pins on the PCB to match up
with the on-board receiver.
One advantage of the AD8196 in an AVR-type application is
that all of the high speed signals can be routed on one side (the
topside) of the board, as shown in Figure 31. In addition to
12 dB of input equalization, the AD8196 provides up to 6 dB of
output pre-emphasis that boosts the output TMDS signals and
Figure 31. Evaluation Board Layout of the TMDS Traces
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allows the AD8196 to precompensate when driving long PCB
traces or output cables. The net effect of the input equalization
and output pre-emphasis of the AD8196 is that the AD8196 can
compensate for the signal degradation of both input and output
cables; it acts to reopen a closed input data eye and transmit a
full-swing HDMI signal to an end receiver. More information
on the specific performance metrics of the AD8196 can be
found in the Typical Performance Characteristics section.
The AD8196 also provides a distinct advantage in receive-type
applications because it is a fully buffered HDMI/DVI switch.
Although inverting the output pin order of the AD8196 on the
PCB requires a designer to place vias in the high speed signal
path, the AD8196 fully buffers and electrically decouples the
outputs from the inputs. Therefore, the effects of the vias placed
on the output signal lines are not seen at the input of the AD8196.
The programmable output terminations also improve signal
quality at the output of the AD8196. The PCB designer, there-
fore, has significantly improved flexibility in the placement and
routing of the output signal path with the AD8196 over other
solutions.
Preliminary Technical Data