Hi TI,
My custoemr assy a system with DS90UB914A. At this time, they made 560 ports with DS90UB914A.
This is a Automotive application.
And they did a link test(10m coax cable) with Cameras(DS90UB913A) and the result is as below;
OK : 554/560 ports
NG : 6/560 ports = 1.071% (Unlock and parity error was occurred)
The system was made according to TI's recommendation.
(Return Loss, Insertion Loss, PCLK Jitter, POC filter... are correct value)
Especially, 1/6 of NG DS90UB914A(worst sample) could not lock the signal even if the cable length is about 2m.
We checked the CMLOUT eye pattern of the NG device and the result was as below
CMLOUT of Unlock device (10m coax cable)
The cross point of CMLOUT is very low. It made jitter margin low, I guess.
Other analysis information of NG device is as below;
- Under AEQ mode, The readback EQ Value(Add:0x4E) is not stable, the read value were 01, 00, 03, 07, 0F, 1F,.........
(everytime dofferent.)
- Changed to the manual Eq mode and write the EQ value to the Add:0x04 register.
Checked all EQ levels (00, 01,03,07,0F,1F,3F,7F,FF) and we could not find a no error EQ level.
(We detected Unlock with All 8 EQ levels.)
- We tested a camera movi and a coclor bar data patterns and the result was almost same. (Many Unlock was detected.)
- They checked a link with many cameras(20) and the worst DS90UB914A could not lock any cameras(10m also 2m).
For your reference, the CMLOUT of Good DS90UB914A is as below(10m coax cable).
The cross point of the eye is almost center and Add:0x4E(EQ calue) is stable .
Anyway, the error rate is over 1% at this time, So we must solve the problem..
My customer should ship the system to end customer(Automotive) soon.
Could you please help us ASAP ?
