TMDS61 & DVB100 Test Data

The data shown below was taken on the TMDS61 & DVB100 digital video switches by Video Storm.  The source (input) is a 1.65 Gbps digital video data stream.  This is slightly faster than the data rate required for 1080p format.

The data plots display the data slicing eye.  Since this is digital video, in order to perfectly recover the original transmitted signal the data "eye" must be completely open.  The gray window in the center of the display show the data eye region.  If the colored traces remain completely outside this region, all compliant receivers will be able to decode the signal without errors.

The data rate for DVI or HDMI is very high, up to 1.65 Gbps.  Signals of this frequency suffer from a large amount of loss and interference when they travel down long cables.  The practical limit for cable distance is 15ft when using 28 AWG cables.  As you can see in the measurement below, the signal is degraded after 15 ft of cable but the eye is still open.  At 30 ft, the eye is completely closed.

The active amplifiers in TMDS61 actually improve the signal quality reducing the jitter and restoring the full amplitude swing.  The output of the TMDS61 after the 15 ft cable is much cleaner.  The TMDS61 is even capable of receiving and retransmitting the signal from the 30ft cable. 

1.65 Gbps data stream through 15 ft 28 AWG cable

 Same signal after going through TMDS61 (15ft cable on input, measured at output)

1.65 Gbps data stream through 30 ft 28 AWG cable

  Same signal after going through TMDS61 (30ft cable on input, measured at output)