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Altera_Forum
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19 years ago

5.0V Devices ?

Hi, I'm trying to drive a 5-volt device , ie CD-Rom drive, with my Cyclone board and was wondering if it's possible at all? Or does Cyclone only suppport 3.3V at its output pins. Would it work ...
Altera_Forum's avatar
Altera_Forum
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19 years ago

You need to look at the data sheet of the other device. Cyclone can drive 5V TTL but not 5V CMOS. Likewise, there are techniques involving the PCI Clamp Diode in order to receive 5V.

Page 11-3 of the Cyclone Handbook details this -

http://www.altera.com/literature/hb/cyc/cyc_c51011.pdf

Apex 20K (non-E) can drive 5V TTL and 5V CMOS by configuring the output pin as an open-drain pin. You then use an external pull-up resistor to get to a 5V level.

Details on pg 46.

http://www.altera.com/literature/ds/apex.pdf