DS90UB929-Q1: What is the latency of the back channel between the DS90UB929 and the DS90UH926

Michael Von Ahnen

Part Number: DS90UB929-Q1

There does not appear to be a specification for the latency of the back channel for the DS90UB929. Our design uses a DS90UH926 as the deserializer. Has this been measured? What about the jitter?

over 5 years ago

0 Casey McCrea over 5 years ago

TI__Guru** 103215 points

Hello Michael,

What latency exactly are you interested in? GPIO? I2C? Something else?

Best Regards,

Casey

0 Michael Von Ahnen over 5 years ago in reply to Casey McCrea

Intellectual 580 points

GPIO latency and jitter going from the 926 to the 929

0 Steven(Shenzhen) Shi over 5 years ago in reply to Michael Von Ahnen

TI__Mastermind 30515 points

Hi, Michael,

For the back channel latency between ub929 and uh926, since the back channel rate is ~5Mbps, the latency from the back channel frame is ~10us.

regards,

Steven

0 Steven(Shenzhen) Shi over 5 years ago in reply to Steven(Shenzhen) Shi

TI__Mastermind 30515 points

regarding the gpio jitter, if the back channel rate is 5Mbps, the back channel GPIO jitter is = 1/(5Mbps / 30) = 30 /5 us = 6us.

To reduce the BC gpio jitter, you can use ux94x with higher back channel rate.

best regards,

Steven

0 Michael Von Ahnen over 5 years ago in reply to Steven(Shenzhen) Shi

Intellectual 580 points

You showed the calculation for your numbers for delay and jitter. Why does 5 MHz back channel imply 10 us delay (is this based on the number of bits sent back) ? Where does the "30" come from in the jitter calculation?

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DS90UB929-Q1: What is the latency of the back channel between the DS90UB929 and the DS90UH926