Choosing device

[Altera_Forum]

Hi, 

I am about to make a new PCB with an FPGA on it. I have used a Cyclone3 development board for test, but now I need to make my own cost optimized board. I am however not sure witch device to use for my design... I could go for a Cyclone 3 or 4 (I need around 55k LE). I need to sample an ADC with 150MSPS, so the speed is also important, but I don't know how to compare the speed-grades. Today I have a Cyclone3 speedgrade 6, but how do I know if 8 is sufficient? Can anyone recommend any articles onthe subject or how you are choosing?  Regards, Morten

[Altera_Forum]

--- Quote Start ---   ... I don't know how to compare the speed-grades. Today I have a Cyclone3 speedgrade 6, but how do I know if 8 is sufficient? Can anyone recommend any articles onthe subject or how you are choosing?   --- Quote End ---    You create your HDL for an example design, and constrain it with TimeQuest.  You then use Quartus to place-and-route the design for various devices.  Your Quartus TimeQuest analysis will then determine whether your design meets timing.  Here's an example where I've done this for the PCIe IP core to determine what speed grades it works in:  http://www.alteraforum.com/forum/showthread.php?t=35678  Cheers, Dave