why FPGA part number representation by Xilinx and Digikey is different?

[param_acclivis]

Hi,

I have observed that Xilinx represents part no as " xczu2eg-sfvc784-1-e" but on Digikey, they represent as" XCZU2EG-1SFVC784E". because of this, I am not able to copy-paste and search part on Digikey. why the representation is different?

[dpaul24]

@param_acclivis ,

Would it not be wise to ask Digikey this question?

[joancab]

The full FPGA part number includes the package type and ball count (sfvc784), speed grade (1) and temperature grade (E). It could simply be they don't have a field for speed grade when entering part numbers. Tbh, I use distributors websites as part selection engines. But I don't enter the full part straight away. Enter the first (xczu2eg) then filter by package, temperature, etc. At the end you will have a list of 3, 5, 7 to choose the right. There is life beyond copy paste.

[dpaul24]

@joancab ,

It could simply be they don't have a field for speed grade when entering part numbers.

They do have it. Digikey " XCZU2EG-1SFVC784E"

[joancab]

So it's just Digikey's way of writing things. I missed that. 

[param_acclivis]

The way you search FPGA on distributors' sites is not bad. what if you have to do this for 1000 part numbers?

[joancab]

If your role is FPGA design and you have to choose a part, you would have 2-3 in mind, maybe 10, but not 1000. I wonder if the whole Xilinx has so many PNs.

Companies have databases of parts, suppliers, supplier reference numbers, etc. That's usually somebody else's full time job, not a development engineer.

Me, as a freelance/ consultant, have created my own PCB databases, most of the parts are passive (a myriad of resistors and capacitors). For prototype manufacturing I don't select manufacturers but list them, for example, as "resistor SMD 0402 2k2 1%" and the assembly house will put one from the make they have. For ICs yes, I go one by one, there aren't so many, specially these days with the trend of everything-on-one-chip. That's part of the job, maybe one nobody likes but it's needed and payed for. 

So, I mean, if you have to peruse a thousand components on Digikey, your role is not a developer one, and if you are a developer you won't be choosing a thousand components.

[param_acclivis]

count the number of FPGA's available in Vivado, or ask any developer how to get this list

[joancab]

Typically, for a new project, you take early decisions, for example, do you need a hard processor? with that you go for Zynq devices or pure FPGA. Then you asses your project size and performance requirements, it should be easy to tell what can be done with a Spartan or Artix-7 and what requires a Virtex-7. I base myself on the product selection guides, for example:

7 Series Product Tables and Product Selection Guide (mouser.com)

So you can have a top view of all the models and from there choose a few alternatives to carry on. For a new project, nobody knows exactly the required size or speed grade required, so most of the times, at prototype stage, a 'more than enough' chip is selected, later on downgraded when the design is nearly finished. Another reason that prevents you from investigating many alternatives. At first design stage because you go for the 'best' and at a second stage because your design is almost frozen.