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Altera_Forum
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16 years ago

Assembling an FPGA board on 2 layers PCB

Hi all, is it possible to build a working board based on a Cyclone II/III FPGA 144pin in QFP package on a 2-layers only PCB? The board would also contain a FTDI device for USB communications and...
Altera_Forum's avatar
Altera_Forum
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16 years ago

(Shot no.2)

You're right about the 2.5V for Cyclone III (Altera messed that up ...). This is a (slight?) complication.

Maybe the ADC can run on 2.5V VccIO. Or else stick with Cyclone II.

A standard 4-layer board has a separation of about 700µ, so we could use use a 0.8 mm thick 2 layer PCB? Anyway the 100nF, 1nF capacitors on each VccInt ot VccIO pin will make up for the 'missing' plane capacitance.