ADV3002-EVALZ AD [Analog Devices], ADV3002-EVALZ Datasheet - Page 21

• Manufacturer Part Number: ADV3002-EVALZ
• Description: 4:1 HDMI/DVI Switch with Equalization, DDC/CEC Buffers and EDID Replication
• Manufacturer: AD [Analog Devices]

APPLICATIONS INFORMATION
HDMI MULTIPLEXER FOR ADVANCED TV
The ADV3002 is a complete HDMI/DVI link switch featuring
equalized TMDS inputs, ideal for systems with long cable runs.
The ADV3002 includes bidirectional buffering for the DDC bus
and CEC line, with integrated pull-up resistors for the CEC line.
Additionally, the ADV3002 includes an EDID replication function
that enables one EDID EEPROM to be shared for all four HDMI
ports. Alternatively, a system standby microcontroller can be
used instead of a dedicated EDID EEPROM to load the ADV3002
SRAM. Simplified application schematics are shown in Figure 33
and Figure 34 illustrating these two options.
TMDS Signals
TMDS signals can be routed from an HDMI connector directly
to the inputs of the ADV3002. Additional components are not
required for the TMDS signals.
DDC Signals
47 kΩ pull-up resistors to 5 V are recommended for the DDC
input signals.
CEC Signal
The CEC buffer in the ADV3002 provides a fully compliant
input in situations where a general-purpose microcontroller is
used to interpret CEC commands. The rise time of the CEC
buffer is set by the time constant of the pull-up resistance and
the capacitance on the node. A 2 kΩ pull-up resistor to 3.3 V is
recommended for optimal output rise times. If a 3.3 V is not
Figure 30. ADV3002 as an HDMI Multiplexer in an HDTV
MAIN PCB
ADV3002
HDMI
SoC
OR
Rx
HDTV SET
Rev. 0 | Page 21 of 28
available when the system power is off, a Thevenin equivalent
2 kΩ pull-up resistor to 3.3 V is shown in Figure 31.
5 V Power
The individual 5 V power from each HDMI source can be routed
to the respective 5 V inputs of the ADV3002. The ADV3002
combines these four 5 V supplies into one labeled AMUXVCC
to support EDID replication and CEC functionality when the
local system power is off. An internal 5 V supply must be provided
so that power is not drawn from the HDMI sources when the
local system power is on. When the local supply is off, this internal
5 V should be high impedance. This can be assured by using a
Schottky diode, as shown in Figure 32.
P5V_A
P5V_B
P5V_C
P5V_D
ADV3002
CEC_OUT
Figure 32. 5 V Power Connections
Figure 31. CEC Circuit
5V_COMBINED
AMUXVCC
3kΩ
6kΩ
5V INTERNAL
CEC_IN
MCU
AMUXVCC
ADV3002