AD8197-EVAL Analog Devices, AD8197-EVAL Datasheet - Page 15

• Manufacturer Part Number: AD8197-EVAL
• Description: 4:1 HDMI/DVI Switch with Equalization
• Manufacturer: Analog Devices

Preliminary Data Sheet
When the AD8197 is powered from a simple resistor network,
as shown in Figure 28, it uses the 5 V supply that is required
from any HDMI/DVI source to guarantee high impedance of
the auxiliary multiplexer pins. The AMUXVCC supply does not
draw any static current; therefore, it is recommended that the
resistor network tap the 5 V supplies as close to the connectors
as possible to avoid any additional voltage drop.
This precaution does not need to be taken if the DDC
peripheral circuitry is connected to the bus downstream of
the AD8197.
AUXILIARY (LOW SPEED) SWITCHING MODES
The AD8197 has three auxiliary switching modes: quad, dual,
and single. These are selected by programming the AUX_SM
bits of the auxiliary device modes register through the serial
control interface. The auxiliary switching mode is independent
of the high speed switching mode whenever the part is
controlled through the serial control interface. When the part is
controlled through the parallel control interface, however, only
quad mode is accessible and the auxiliary switching mode
cannot be independently controlled.
Figure 28. Suggested AMUXVCC Power Scheme
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Quad Switching Mode
This is the default mode. In quad mode, the AD8197 behaves
like a 4:1 auxiliary link multiplexer, routing groups of four
auxiliary input signals to the four-signal output. The user can
select which group of inputs is routed to the output by program-
ming the AUX_CH bits of the auxiliary device modes register
through the serial control interface in accordance with the
switch mapping listed in Table 13. Alternately, the user can
select which group of inputs is routed to the output by setting
the PP_CH bus of the parallel control interface in accordance
with the switch mapping listed in Table 27.
Dual Switching Mode
In this mode, the AD8197 behaves as a locked dual [8:1]
auxiliary signal switch. The two 8:1 switches share the channel
select input and, therefore, switch together. The user selects
which two out of the eight possible input groups are routed to
the output by programming the AUX_CH bits of the auxiliary
device modes register in accordance with the switch mapping
listed in Table 14. This mode is only accessible through the
serial control interface.
Single Switching Mode
In this mode the AD8197 behaves as a single 16:1 TMDS
channel multiplexer; a single channel, out of a possible 16, is
routed to all of the outputs. The user selects which input
channel is routed to the outputs by programming the AUX_CH
bits of the auxiliary device modes register in accordance with
the switch mapping listed in Table 15. This mode is only
accessible through the serial control interface.
AD8197