Looking for FPGA board with at least four ADC

[rick_apu]

I am looking for an FPGA board that has at least 4 ADCs on it, or an FPGA board and a separate ADC board that can be connected. General requirements:

1) The FPGA board must use a Xilinx series 7 so that Vivado can be used as the development environement.

2) The ADCs don't need to be very fast, 100KSPS or 50KSPS is good enough with at least 16 bits of resolution.

A key requirement is that the data acquisition from the ADCs must be simultaneous (that's why we believe we need an FPGA).

Do you have any suggestions for Digilent products or Digitent plus Analog Devices products that will meet this need?

[zygot]

Any board that has an FMC connector can have 4 ADCs on it. Digilent sells the Nexys Video and Genesys2 and Zedboard. Most boards made by Xilinx have LPC and HPC FMC connectors. I have used the ADS4449 evaluation board from Texas Instruments with the Genesys2. You need to purchase an adaptor board to connect the ADS4449 EVM to FMC. Expect to do a lot of homework to use it. I also had to remove the board retention pins on the EVM. But, it can be done with quite a bit of effort. I've also used EVAL-AD7616SDZ plus SPD-I-FMC adaptor from ADI. I've also use the EVAL-AD7761FMCZ ( no adaptor necessary ). The ADI demo boards are "audio" range products. Read the data sheets very carefully to see it they are  appropriate for your needs. As I recall one of these devices does 8 channels with simultaneous sampling. There may be other demo boards out there. You will likely have to do some work to drive all of these boards with a particular signal.

Warning, there's a lot of things to consider when doing A/D and most A/D demo boards are designed to demonstrate the data sheet specs; not provide a general purpose A/D board. I only give advice and opinions on things that I have experience with and trust me I know of what I write. 

If you don't need 4 simultaneous A/D conversions ( not all multi-channel ADCs sample on all channels simultaneously ) a cheap alternative might be to build your own analog mux and use the audio codex available on most Digilent FPGA boards.

I haven't found a good FPGA board with 4 channels of simultaneous ADC. Terasic has a few cheap FPGA boards with multiple channels of ADC ( I don't think that they are simultaneous sampling...). For under $100 the Terasic DE0-NANO is a great development board. You'll have to use Quartus as Terasic is an Altera partner. Mouser sells them at a reasonable markup.

In general vendors of ADC DAC conversion boards get a pretty nice profit margin and I am unaware of anybody challenging their dominance.

A key requirement is that the data acquisition from the ADCs must be simultaneous (that's why we believe we need an FPGA)

I'm not sure what your thinking is on this. Simultaneous sampling eases coherent processing of multiple channels but you can compensate if using multiplexed sampling. Be aware that for ADCs with multiple channels you have a problem with one channel corrupting the others. The data sheets usually don't make this specification prominent. For low sample rates an FPGA will be doing nothing between samples, as will a micro-controller, PC or most anything else. Figure out exactly what your requirement is. I only mention this because your statement suggests to me that perhaps you need to do some reading about conversion between the analog and digital domains.

[zygot]

@rick_apu,

I was hoping that someone would have addressed your question with a more concrete and immediate answer ( get the notion that I have a hard time letting go of things? ). I've been looking for affordable FMC conversion mezzanine boards for years and an still looking. The fact is that most A/D interface applications require very specific design choices to be made at the design level so it's hard to provide a really good inexpensive solution for a wide range of applications.  Let me know how you make out.