DPL's Preliminary "48G Reference StandardTM Testing Begins

February 7, 2020

As we standby for some final software changes to arrive for our new test instruments offers us a bit of time to start to do some preliminary testing for 48G cables. The quantity of tests has increased dramatically as we begin to dive into this huge world of 48G. For the first time the speed that makes up the UI has increased into a double digit time frame. From 166ps back in the day of 6Gbps per channel range down to a mere 83ps at 12Gbps. It means every single instruction in the video data has to be done in twice the speed with razor sharp accuracy. And, to just makes things a bit harder, the signal level minimums have been reduced to almost a third which means the signal riding on your cables are that much closer to the noise floor. These new instruments have the ability to make up some operator time by allowing the noise measurement to be achieved with just a stroke of a mouse click.

            To further add to the workload, video performance measurements should really include 5 different data rates starting at 3Gbps and sweeping up to 6Gbps, 8Gbps,10Gbps, and 12Gbps. This also includes rise time, fall time, jitter, skew and deviation. These will require customized DPL Mask limits to improve the products performance and reliability. The reason for these additional tests becomes even more important due to the large operating envelope we are now working with. Insertion loss curves have to be somewhat linear in order to provide this level of performance over the entire HDMI spectrum.

            DPL’s Argumentative MatrixTM has been updated to be used in DPL’s new 48G Reference StandardTM. Some of the functions that are carried over from Rev 2.0 will remain at elevated stress limits that we have been successfully using. However, due to the higher data rates and huge operating envelope the high-speed data tests needs much more attention. By way of our preliminary testing procedures we have experienced anomalies that may have not been caught at lower 6Gbps data rates and the increased limits within the Argumentative MatrixTM itself.

            The waveform illustrated displays a .5-meter 48G HDMI cable with a serious issue on Channel 3. After dissection of the cable it was found that the dielectric chemistry within the cable caused these phase distortions to take place. All 5 samples were the same suggesting the entire dye lot may have been affected by this to some degree raising concern. i.e. No Video.

            We have had several cable firms ask what our thoughts are about the HDMI announcement of their Ultra High-Speed testing services. DPL has always supported these efforts with all of our members. In DPL’s eyes it takes a far more stringent approach to provide the best performance products in the industry by way of our elevated test and measurement methodology.

            This cable test sample is a perfect example of why the need for increased stress limits be performed which only DPL provides by way of its Argumentative MatrixTM. With this methodology far more test data can be gathered to forecast production yields, reliability and peace of mind.

As DPL continues with these preliminary test procedures, we will keep all of you posted.