11-24-2018 03:59 PM
Hello Admins and Mods:
I am currently working on a design project that requires the implementation of FPGAs and ADCs with certain specs.
I have a couple of related questions regarding the development and evaluation boards.
Any relevant feedback (especially with diagrams/documentation) is greatly appreciated.
11-24-2018 10:27 PM
1 - The only FPGAs with built-in ADC I know are the 7 Series with their XADC but it's limited to 1 Msps and shared among all ports you capture.
2 - Almost any ADC can interface the SP605. I think you mean a plug-in board.Didn't you find any in either google or Xilinx>Products>Boards?
3 - FPGA don't have "ports" but banks. In principle you can connect any I/O to any pin in any bank. Then restrictions come. First of all is bank voltage, you want it the same as the chip you are interfacing, this usually makes you interfacing a chip to the same bank or banks with the same voltage. Second is speed and standard. For an ADC at 10 Msps you can still choose between a parallel interface (either single ended or differential) which is a lot of pins (64 only data) or serial which means up to 16*10 = 160 MHz, I think the Spartan 6 can cope with that.
The SP605, as far as I remember, only has that "high-end" mezzanine connector for expansion. The good news is that it has lots of pins and allows for high speed. The bad news is there are few boards for it and if you make your board, won't be as cheap as a two layer pcb with through hole pin header.
So I'm afraid to say there isn't an easy solution. My feeling is that the SP605, even if old and simple is still too big for your project, I would rather have started with a simpler board, a break-out style with plenty of 2.54-mm pinheaders where you can wire up things easily. Keep in mind those connectors will most probably work at 10 MHz (parallel interface) but probably won't at 160 MHz (serial interface) for signal integrity reasons.
11-24-2018 09:28 PM
(1) No.
(2) That appears to be a challenge. A chip like the LTC2325 appears to be suitable (although I'm not sure about the demodulation - I'm not familiar with that), but good luck finding an appropriate development board.
(3) Most high-end FPGA expansion boards use FMC; the SP605 has one FMC port.
11-24-2018 10:27 PM
1 - The only FPGAs with built-in ADC I know are the 7 Series with their XADC but it's limited to 1 Msps and shared among all ports you capture.
2 - Almost any ADC can interface the SP605. I think you mean a plug-in board.Didn't you find any in either google or Xilinx>Products>Boards?
3 - FPGA don't have "ports" but banks. In principle you can connect any I/O to any pin in any bank. Then restrictions come. First of all is bank voltage, you want it the same as the chip you are interfacing, this usually makes you interfacing a chip to the same bank or banks with the same voltage. Second is speed and standard. For an ADC at 10 Msps you can still choose between a parallel interface (either single ended or differential) which is a lot of pins (64 only data) or serial which means up to 16*10 = 160 MHz, I think the Spartan 6 can cope with that.
The SP605, as far as I remember, only has that "high-end" mezzanine connector for expansion. The good news is that it has lots of pins and allows for high speed. The bad news is there are few boards for it and if you make your board, won't be as cheap as a two layer pcb with through hole pin header.
So I'm afraid to say there isn't an easy solution. My feeling is that the SP605, even if old and simple is still too big for your project, I would rather have started with a simpler board, a break-out style with plenty of 2.54-mm pinheaders where you can wire up things easily. Keep in mind those connectors will most probably work at 10 MHz (parallel interface) but probably won't at 160 MHz (serial interface) for signal integrity reasons.