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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

what is possible depends upon what the target is specified for

i would say that 100MHz is a no go, as 100MHz is not a rectangular but sinusiodal 1. frequency of or clock. so your 100MHz will need the 3. and at minimum the 5. harmonic so you get 300MHz and 500MHz as well. to handle that with a 2 layer pcb .. no further comment

okay i knew of designs running sdram at 100MHz on a 2 layer pcb but i wouldn#T do that.

go for at least 4 layer pcb, that will enable you to provide low impedance |Z| of you power supply