AD8197AASTZ-RL Analog Devices Inc, AD8197AASTZ-RL Datasheet - Page 23

• Manufacturer Part Number: AD8197AASTZ-RL
• Description: IC,Telecom Switching Circuit,QFP,100PIN,PLASTIC
• Manufacturer: Analog Devices Inc

Specifications of AD8197AASTZ-RL

• Function: Switch
• Circuit: 1 x 4:1
• On-state Resistance: 50 Ohm
• Voltage Supply Source: Single Supply
• Voltage - Supply, Single/dual (±): 3 V ~ 3.6 V
• Current - Supply: 40mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 100-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATION INFORMATION
The AD8197A is an HDMI/DVI switch, featuring equalized
TMDS inputs and pre-emphasized TMDS outputs. It is in-
tended for use as a 4:1 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 AD8197A is designed to have an HDMI/DVI receiver
pinout at its input and a transmitter pinout at its output, which
makes the AD8197A 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
AD8197A is used in receiver type applications, it is necessary to
change the order of the output pins on the PCB to align with the
on-board receiver.
One advantage of the AD8197A in an AVR-type application is
that all of the high speed signals can be routed on one side (the
top side) of the board, as shown in Figure 31. In addition to
12 dB of input equalization, the AD8197A provides up to 6 dB
of output pre-emphasis that boosts the output TMDS signals
and allows the AD8197A to precompensate when driving long
PCB traces or output cables. The net effect of the input
equalization and output pre-emphasis of the AD8197A is that
the AD8197A can compensate for the signal degradation of
both input and output cables; it acts to reopen a closed input
Figure 31. Layout of the TMDS Traces on the AD8197A Evaluation Board (Only Top Signal Routing Layer is Shown)
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data eye and transmits a full-swing HDMI signal to an end
receiver. More information on the specific performance metrics
of the AD8197A can be found in the Typical Performance
Characteristics section.
The AD8197A 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 AD8197A on
the PCB requires a designer to place vias in the high speed
signal path, the AD8197A 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 AD8197A. The programmable output terminations also
improve signal quality at the output of the AD8197A. The
PCB designer, therefore, has significantly improved flexibility
in the placement and routing of the output signal path with
the AD8197A over other solutions.
CABLE LENGTHS AND EQUALIZATION
The AD8197A offers two levels of programmable equalization
for the high speed inputs: 6 dB and 12 dB. The equalizer of
the AD8197A supports video data rates of up to 2.25 Gbps,
and as shown in Figure 14, it can equalize more than 20 meters
of 24 AWG HDMI cable at 2.25 Gbps, which corresponds to the
video format, 1080p with deep color.
AD8197A