Other Parts Discussed in Thread: LMH1229
About the current issues at our company.
Our testing uses color bars and pathological signal sources.
For both signal sources, the transmission distance for pathological signals was inferior to that for color bar signals in about 10% of cases in this production, according to our target product standards (not the specifications of device data sheets). I am.
After replacing the device (LMH1297), the target transmission distance was secured even for pathological signals.
Regarding this matter, the FAE in charge of your company responded as follows.
>75m spec is Color Bar, and Pathological doesn't seem to pass.
When I made a detailed inquiry, I was instructed to ask questions directly at E2E, so I decided to ask questions (Q1-1, 2, 3, Q2, Q3).
・Is the transmission distance (*1) listed in the LMH1229 data sheet possible even with pathological signals?
*1:LMH1297 is rated for 75m B1694A. This is equivalent to about 90-100m of 5.5CUHD cable used in Japan.
When I inquired with our FAE, I was told that pathological signals would not pass.
Regarding this matter, there is no such description in the data sheet (*1), so I would like to confirm accurate information. (Q1-1)
Also, if this is true, I would like an answer as to how much transmission distance can be achieved with pathological signals (Q1-2).
I would like to see a revision of the data sheet or some kind of official announcement regarding this matter. (Q1-3)
Comment: When we considered adopting LMH1297 several years ago, there was no such information available.
When we actually evaluated it, the transmission distance was not inferior with pathological signals.
For reference, here is an example of the latest documentation for another device.
The document I received (LMH1229) clearly states the performance difference between color bars and pathological signals as shown below.
1.Long cable reach capability
・100m+ 12G color bar cable reach
・300m HD cable reach
・600m SD cable reach
2.Robust pathological pattern performance
・Only solution to support 90m+ 12G pathological cable reach
・Next, does this mean that this LMH1297 cannot achieve the performance described in the data sheet with pathological signals in other formats (1.5G, 3G, 6G) other than 12G-SDI? (Q2)
・Thirdly, what is the cause of the 12G-SDI pathological signal not passing through with the 75m spec? (Q3)
The fact that the color bar passes means that the problem is not the EQ (equalizer), but the subsequent reclocker's performance.
that's all
Best Regards,
Tanaka
