{"action":"created","issue":{"url":"https://api.github.com/repos/m-labs/sinara/issues/99","repository_url":"https://api.github.com/repos/m-labs/sinara","labels_url":"https://api.github.com/repos/m-labs/sinara/issues/99/labels{/name}","comments_url":"https://api.github.com/repos/m-labs/sinara/issues/99/comments","events_url":"https://api.github.com/repos/m-labs/sinara/issues/99/events","html_url":"https://github.com/m-labs/sinara/issues/99","id":193385496,"number":99,"title":"metlino IO breakout: specification discussion","user":{"login":"jbqubit","id":20543958,"avatar_url":"https://avatars.githubusercontent.com/u/20543958?v=3","gravatar_id":"","url":"https://api.github.com/users/jbqubit","html_url":"https://github.com/jbqubit","followers_url":"https://api.github.com/users/jbqubit/followers","following_url":"https://api.github.com/users/jbqubit/following{/other_user}","gists_url":"https://api.github.com/users/jbqubit/gists{/gist_id}","starred_url":"https://api.github.com/users/jbqubit/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jbqubit/subscriptions","organizations_url":"https://api.github.com/users/jbqubit/orgs","repos_url":"https://api.github.com/users/jbqubit/repos","events_url":"https://api.github.com/users/jbqubit/events{/privacy}","received_events_url":"https://api.github.com/users/jbqubit/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":13,"created_at":"2016-12-04T23:44:26Z","updated_at":"2016-12-10T19:35:12Z","closed_at":null,"body":"ARTIQ hardware plan calls for a 19\" rack breakout for digital signals. Proposed name: PCB_io_19in_sma. Motivation is low-latency digital IO, coaxial cable drivers (50 Ohm) and electrical isolation. Proposed specification follows. Informed by email discussion 6/28 with @gkasprow, @sbourdeauducq, @jordens and @dhslichter. \r\n\r\n# front-side connectors\r\n- electrical interface: support for interface with kasli and metlino_vhdci\r\n- 32 isolated SMA connectors in two rows \r\n\r\n# back-side connector\r\n- aperture for Kasli IO\r\n    - 2 SFP connector\r\n    - kasli board would be mounted horizontally and plugged into 100 mil header on PCB_io_19in_sma\r\n    - this forward-looking compatability requires solidifying design choices for kasli: PCB geometry, header location, header logic \r\n- VHDCI connector (eg Molex SD-71430-015)\r\n    - 32-differential LVDS\r\n- AC connector is IEC 320 C13/C14\r\n\r\n# power \r\n- source: 220V at 50 Hz or 110V at 60 Hz\r\n- supply: AC DC converter of some sort\r\n\r\n# geometry\r\n- breakout is 19\" rack panel, 1 U height \r\n\r\n# digital interface to ARTIQ control hardware\r\n- assume one of the following is supplied by end user\r\n    - VHDCI cable from PCB_metlino (LVDS)\r\n    - PCB_kasli mounted as a mezzanine and commanded by SFP\r\n\r\n# SMA drivers/receivers  \r\n- direction (input/output) user configurable in groups of 8 \r\n- optional galvanic isolation breaks ground loops independently for each SMA \r\n    - jumpers permit use (or not) of isolation IC\r\n    - @dhslichter recommends Si8640, 4 channel, 150Mbit,  13 ns propagation delay, ~350 ps jitter; $4/chip\r\n    - to support reconfigurable direction\r\n        - use 4 Si8640 for each bank of 8 SMA\r\n        - Si8640 has pin to toggle output drive on/off, use to select direction\r\n    - SN74BCT25245 is octal, reconfigurable direction, 25-ohm driver\r\n- if bank of 8 is configured as _input_\r\n    - install jumper to choose direction of Si8640 and SN74BCT25245\r\n    - install 1 kohm input termination\r\n- if bank of 8 is configured as _output_\r\n    - install jumper to choose direction of Si8640 and SN74BCT25245\r\n    - install 50 Ohm output termination (series resistor as close to the driver)\r\n\r\nIt would be convenient for testing of v0.1 Sinara hardware if this PCB is available to ship at same time. \r\n\r\nTPH edit: typo\r\nJWB edit: as in comment on 12/6"},"comment":{"url":"https://api.github.com/repos/m-labs/sinara/issues/comments/266232219","html_url":"https://github.com/m-labs/sinara/issues/99#issuecomment-266232219","issue_url":"https://api.github.com/repos/m-labs/sinara/issues/99","id":266232219,"user":{"login":"hartytp","id":21218399,"avatar_url":"https://avatars.githubusercontent.com/u/21218399?v=3","gravatar_id":"","url":"https://api.github.com/users/hartytp","html_url":"https://github.com/hartytp","followers_url":"https://api.github.com/users/hartytp/followers","following_url":"https://api.github.com/users/hartytp/following{/other_user}","gists_url":"https://api.github.com/users/hartytp/gists{/gist_id}","starred_url":"https://api.github.com/users/hartytp/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/hartytp/subscriptions","organizations_url":"https://api.github.com/users/hartytp/orgs","repos_url":"https://api.github.com/users/hartytp/repos","events_url":"https://api.github.com/users/hartytp/events{/privacy}","received_events_url":"https://api.github.com/users/hartytp/received_events","type":"User","site_admin":false},"created_at":"2016-12-10T19:35:12Z","updated_at":"2016-12-10T19:35:12Z","body":"IMO individual isolation of each channel is not necessary. Having groups of 4 (or 8 if it helps) isolated should be fine. "}}
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