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Altera_Forum
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14 years ago

Cyclone III with 5v inputs

I'm trying to connect approximately (16) 5v TTL inputs into a Cyclone III eval board, the terasic de0 [1]. These are all input towards the FPGA only. The eval board has (2) 40-pin IDC headers for t...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

@jshamlet: Thanks for the info. I've definitely seen those IDT quickswitches before, but I've never used one.

TI is mega fast on the samples. I ordered yesterday 1pm, this morning at 9am it was in my door. Maybe I'll dead bug one soon just to watch it work, and then design my converter PCB around it.

Thanks for the link to the videos.

can i attach the output of the ti chip directly to the connector going to the cyclone iii? ie without a series resistor?

The application note (http://www.ti.com/lit/an/scda003b/scda003b.pdf) and datasheet (http://www.ti.com/lit/ds/symlink/sn74cbtd3384.pdf) doesn't seem to cover it explicitly.

should i connect the fpga ground to the ground of the system i'm receiving the 5v ttl from?

Thanks,

Keith