Sfp-experimenter » History » Revision 4
Revision 3 (laforge, 10/07/2018 06:55 AM) → Revision 4/7 (laforge, 03/05/2019 01:55 PM)
{{>toc}} h1. sfp-experimenter The Osmocom SFP experimenter board a small circuit board for experiments with (usually fiber optical) transceivers in SFP form factor. You can use it for e.g. # 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 # attach some I2C adapter to the I2C pins twin brother of the SFP module in order to re-program it # The SFP transceivers exhibit a symmetric/differencial interface for Rx and Tx. The sfp-experimenter board [[sfp-breakout]] board. It contains an on-board differential transmitter and receiver LVDS receiver/transmitter circuits, so you can transmit/receive normal use single-ended signals. If you're interested in transmitting differential signals, please see signals on the [[sfp-breakout]] board instead. It's like the SFP experimenter board, but contains no differential transmitter + receivers. electrical side. h2. Schematics h2. Schematics / Design files The schematics / design files are kept in git at https://git.osmocom.org/osmo-small-hardware/tree/sfp-breakout You can see the design discussion in #3314 and notes from board-bringup at #3523 h2. Photos !sfp-experimenter.jpg! h2. Availability h2. Errata h3. sfp-experimenter v1 h4. R6 pull-down re-work 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. !sfp-experimenter-r6-rework.jpg!
