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I have a adc AD7829 which is parallel 8 bits digital outputs.

I consider using cable to transfer digital (out) data.

Circuit likes:

------------------------------------------------------------
Board 1
------------------------------------------------------------
| [I/V Converter] -> [Analog Buf] -> [ADC]->[Digital Buf]  |
------------------------------------------------------------
                                                ||
                                         Parallel Cable ~3M
                                                ||
------------------------------------------------------------
Board 2                                         ||
------------------------------------------------------------
|                      [PC Host] <- [FPGA]<-[Digital Buf]  |
------------------------------------------------------------

I read here

Long distance(>2M) doesn't seems to SPI/I2C... etc. IC-IC protocol.

So I thought maybe Parallel Cable not is good choice for transfer with cable.

Should I add Serder IC convert 8bits parallel signal to LVDS with clock?

Or does any good others suggestion for this circiut?

Many thanks!

Edit

Add SPEC

  • Before analog input: 8 channels photodiode
  • Analog input: Pulse, R/F time ~6us
  • I/V converter: OPA192

I think that 1Mbps sample rate ADC should be enough.

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  • \$\begingroup\$ We don't know what you want to do and how fast. Why not open up the specs and numbers to have an idea what to answer. I2C can go multiple meters if properly designed, albeit with compromise on speed \$\endgroup\$
    – Justme
    Commented Nov 20, 2022 at 14:57
  • \$\begingroup\$ Why can't the A2D be on board 2? Which serdes are you considering? \$\endgroup\$
    – Andy aka
    Commented Nov 20, 2022 at 14:59
  • \$\begingroup\$ Hi @Justme: Sorry, I'll add detailed spec. \$\endgroup\$
    – curlywei
    Commented Nov 20, 2022 at 14:59
  • \$\begingroup\$ Hi @Andyaka: You means pass signal with analog? AFAIK, digital signal should be better for transfer than analog signal \$\endgroup\$
    – curlywei
    Commented Nov 20, 2022 at 15:06
  • \$\begingroup\$ @curlywei unjustified. When we transmit radio, we use analogue radio methods and that works from Pluto to earth. Designed properly, analogue over 3 metres compared to 8 bits of parallel data is likely to be just as reliable if not more. \$\endgroup\$
    – Andy aka
    Commented Nov 20, 2022 at 15:27

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