DS90UB948-Q1: DS90UB948 LOCK output is different from IC spec.

Wang Lingying

Part Number: DS90UB948-Q1

Hello sirs,

DS90UB948 LOCK output is different from IC spec.

The waveform is showed as below. The channel 1 is LVDS input signal of DS90UB947, the channel 4 is LVDS output of DS90UB948, the channel 3 is PDB signal of DS90UB948, and the channel 2 is LOCK output signal of DS90UB948.

Would you help me to check the LOCK output is OK or not. If not OK, please help me to solve this problem.

over 7 years ago

0 Steven(Shenzhen) Shi over 7 years ago

TI__Mastermind 30515 points

Lingying,

From the waveform, it seems the LOCK is correct. you focus on Ch2 and Ch4 signals, the LVDS output of UB948 is relative with LOCK more closely.

0 Wang Lingying over 7 years ago in reply to Steven(Shenzhen) Shi

Prodigy 85 points

Hi Steven,

We also test the LOCK signal of DS90UB924, the LOCK signal is showed as below.

We want to know the difference, why the LOCK signal is different?

0 Steven(Shenzhen) Shi over 7 years ago in reply to Wang Lingying

TI__Mastermind 30515 points

Lingying,
the UB924 is different from UB948.
1. UB948 needs to tolerate the 8 LVDS inputs
2. the lock signal also relies on input data stability
so you can't understand they (UB924 and UB948) have same status of the LOCK indication, but the work theorem is same. the CDR need detect the correct and stable signals and then output the 'LOCK' indication.

best regards,
Steven

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DS90UB948-Q1: DS90UB948 LOCK output is different from IC spec.