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open-ephys / headstage-isolation-board

isolation board for RHD headstge, electrically decouples headstage from aq. board
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Add LVDS termination resistors #2

Closed jvoigts closed 8 years ago

jvoigts commented 10 years ago

quoting reid: The ADN4664 LVDS-to-CMOS converter chips you use do not include a 100 ohm termination resistor, if I read the datasheet for these parts correctly. So I think you should add 100 ohm resistors between MISO1+ and MISO1-, and between MISO2+ and MISO2- on the headstage side, just before the ADN4664 chips.

Without the termination resistors, LVDS will work for cables lengths of ~2 meters (in my experience), but you'll have problems with reflections on longer cables if these lines aren't terminated properly.

jvoigts commented 8 years ago

should be fixed in af49a08724519d4423b0862b54a69917de73b75f