DS90UB954-Q1: FC bit rate calculation

Ben Kuo

Part Number: DS90UB954-Q1

Dear team,

customer study our app note - SNLA267A.

And they have a question about *2.1.1.5 Clocking and Frequency Selection Example*.

There is a constant value 80 in FC rate equation.

Could you guide us the *80* comes from? How we get this constant value?

FC Rate = 2×80(f0 ) = 160(25M) = 4 Gbps

Regards,

0 Sally Cheung95 over 4 years ago

Hi Ben,

80 comes from an internal multiplier from the PLLs

Thanks,
Sally

0 Ben Kuo over 4 years ago in reply to Sally Cheung95

Hi Sally,

My customer have some issue about 2G sync mode calculation.

Are this equation suitable to calculate throughput in 2G mode if we change BC=F0(25MHz) in sync mode?

BC=f0

FC=80*f0=2Gbps

Regards,

0 Sally Cheung95 over 4 years ago in reply to Ben Kuo

Hi Ben,

if you want to change to 2G mode, simply change the back channel speed to 25 Mbps. Leave the reference clock at 25 MHz.

Thanks

Sally

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