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ADN2531

Hi, 

We try to convert USB 3.1 to optical communication.(application: 'USB 3.1 Active Optical Cable')

Can I use 'Laser driver(ADN2531)' to convert USB 3.1 to optical?

Is it possible to configure it as follows?

   USB Host --<Laser Driver -- TOSA -- Fiber optic -- ROSA -- Limiting Amp.>-- USB Device 

and

Do you have any advice/command or device to suggest?

Thanks,

hjkim

  • Dear Hjkim,

    ADN2531 is an optical physical layer product. It converts input signal from electrical to optical domain, working with a laser diode. In general, we recommend AC coupled signal input to ADN2531.

    In an AC coupled interface, it presents a low frequency cutoff behavior with a recommended 25ohm transmission characteristic impedance and the applied AC coupled capacitance.

    Therefore, when the USB3.1 data stream presents sort of "idle" periods (no data signal at all), the AC coupled interface

    could generate BER in the loop of USB Host --<Laser Driver -- TOSA -- Fiber optic -- ROSA -- Limiting Amp.>-- USB Device.

    I would strongly recommend you to talk with your USB3.1 system design engineer on this. See if there is any existing data link layer solution that can convert a legacy USB3.1 data stream (protocol) to a continuous, random pattern mode data stream. 64B/66B encryption to all USB3.1 data (payload and control) could be a solution. Otherwise, I would say any high-speed laser diode driver solutions could be a potential BER prone device in your promoted data path:

    USB Host --<Laser Driver -- TOSA -- Fiber optic -- ROSA -- Limiting Amp.>-- USB Device.

    Best Regards,

    Dongfeng