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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
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14 years ago

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The TI 74CBTD3384C

http://www.ti.com/lit/ds/symlink/sn74cbtd3384c.pdf

buffers used on the MAX II PCI development kit are bus-switches with the diode internal to the device. You can power them from 5V and they'll clamp bidirectional signals to 3.3V levels.

I've used a bunch a bus switches on lots of designs, but never realized they had parts with the diodes internal to the devices.

Cheers,

Dave

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Thanks Dave for your help.

I would certainly prefer something with less external parts required.

I sampled these today from TI, although they only had the DBQ(SSOP/QSOP) parts available. I prefer SOIC with the larger 1.27mm pitch. I've soldered the SOIC before, and they weren't bad. The SSOP have half the pitch.

Any experience hand soldering these?

Thanks,

Keith