AnsweredAssumed Answered

ADN4604 as HDMI Switcher

Question asked by JoryOlson on May 10, 2016
Latest reply on May 10, 2016 by JoryOlson

Figure 51 on page 32 of the Rev A datasheet for the ADN4604 shows a 16 input/16 output HDMI crosspoint switch.  However, I don't see how it is possible to configure the ADN4604 so that it will accept HDMI signals on the input and output HDMI compliant signal levels on the outputs. 

 

The HDMI version 1.3a specification says that standard HDMI signals are 400mV to 600mV (singled-ended) with the maximum positive swing being at AVCC (3.3V nominal).  That means that at nominal voltages an HDMI signal will swing from 2.8V to 3.3V.  See Figures 4-13 and 4-14 on page 55 of the attached HDMI specification.  This means that the common-mode voltage of an HDMI output is nominally 3.05VDC (the center line shown in Figure 4-14).

 

To be precisely compatible with the HDMI specification, VH-DC (FIgure 44, page 21 of the ADN4604 datasheet) should be VTTO and VL-DC should be 2.8VDC.  I do not see how to configure the ADN4604 to get those signal levels.  It appears to me that the output common-mode voltage for the ADN4604 will always be lower than VTTO and the output swing will be less than 800mV pk-pk.

 

Please tell me how to configure the ADN4604 to implement the application shown in Figure 51 on page 32 of the ADN4604 datasheet (Rev A) using HDMI compliant signaling.

Attachments

Outcomes