Sfp-experimenter » History » Version 4
laforge, 03/05/2019 01:55 PM
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3 | 1 | laforge | h1. sfp-experimenter |
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5 | 4 | laforge | The Osmocom SFP experimenter board a small circuit board for experiments with (usually fiber optical) transceivers in SFP form factor. |
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7 | 4 | laforge | You can use it for e.g. |
8 | # transmitting your own signals / waveforms (not restricted to Ethernet or CPRI) over fiber optics. This is e.g. useful if you need galvanic isolation between digital circuits, or need long-distance transmission |
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9 | # attach some I2C adapter to the I2C pins of the SFP module in order to re-program it |
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10 | # The SFP transceivers exhibit a symmetric/differencial interface for Rx and Tx. The sfp-experimenter board contains an on-board differential transmitter and receiver so you can transmit/receive normal single-ended signals. |
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12 | If you're interested in transmitting differential signals, please see the [[sfp-breakout]] board instead. It's like the SFP experimenter board, but contains no differential transmitter + receivers. |
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14 | h2. Schematics / Design files |
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16 | The schematics / design files are kept in git at https://git.osmocom.org/osmo-small-hardware/tree/sfp-breakout |
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18 | 3 | laforge | You can see the design discussion in #3314 and notes from board-bringup at #3523 |
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20 | 1 | laforge | h2. Photos |
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22 | !sfp-experimenter.jpg! |
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24 | h2. Availability |
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26 | h2. Errata |
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28 | h3. sfp-experimenter v1 |
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30 | h4. R6 pull-down re-work |
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32 | there was a need to place a bias resistor from RD_N to ground (pin4 on ic2) or the whole board would not work. ic2 has internal 100ohm prom pin3 to pin4 and pullups of ~300k to vcc. 100k pulldown on one leg pushes it into the proper operating range. due to the 100ohm its not neccessary to have more than one pulldown. |
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34 | !sfp-experimenter-r6-rework.jpg! |