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Altera_Forum
Honored Contributor I
1,682 Views

Cyclone IV GX Transceiver Starter Kit nterface with ADC module

I wonder who has done a project that interface the Cyclone IV GX transceiver starter kit with an ADC module. I need an ADC module having sampling frequency up to at least 20Mhz. What should I consider to choose the ADC module and what ADC module is best compatible to my FPGA.

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Altera_Forum
Honored Contributor I
68 Views

 

--- Quote Start ---  

I wonder who has done a project that interface the Cyclone IV GX transceiver starter kit with an ADC module. I need an ADC module having sampling frequency up to at least 20Mhz. What should I consider to choose the ADC module and what ADC module is best compatible to my FPGA. 

--- Quote End ---  

 

 

How were you planning on interfacing to the ADC? The Starter kit does not have an HSMC connector. 

 

http://www.altera.com/products/devkits/altera/kit-cyclone-iv-starter.html 

 

If you are planning on using the kit, then perhaps you can use the transceivers on the board PCIe connector. There are JESD204A/B/C ADCs from Texas Instruments and NXP. Perhaps they have an evaluation kit with SMA connectors that you can use. You would also need to buy a PCIe-to-SMA breakout cable. Samtec sell them. 

 

If you have not purchased your kit yet, then you might want to think about using the Cyclone IV GX Development kit, since that has an HSMC connector.  

 

Terasic have FPGA boards and ADC boards, you should look at their products: 

 

http://www.terasic.com.tw/en/ 

 

Cheers, 

Dave
Altera_Forum
Honored Contributor I
68 Views

I'm planning to use an ADC to sample a signal with 10Mhz frequency and then transmit it to Cyclone IV.  

Do you mean JESD204A has PCIe connector and I need a PCIe-to-SMA breakout cable to connect it with Cyclone IV? 

I see the Cyclone IV has both a SMA connector (if I do not misunderstand it) and a PCIe.
Altera_Forum
Honored Contributor I
68 Views

I have no idea about how to choose appropriate ADC. I don't know much details about protocols and standard. Could you explain more about it ?

Altera_Forum
Honored Contributor I
68 Views

 

--- Quote Start ---  

I'm planning to use an ADC to sample a signal with 10Mhz frequency and then transmit it to Cyclone IV.  

 

--- Quote End ---  

 

how are you planning on transmitting the samples? 

 

If the ADC outputs 16-bit samples, then you would need 16 bits of I/O. The Cyclone IV starter kit does not have much I/O, so I'm not sure you will be able to use it. 

 

 

--- Quote Start ---  

 

Do you mean JESD204A has PCIe connector and I need a PCIe-to-SMA breakout cable to connect it with Cyclone IV? 

I see the Cyclone IV has both a SMA connector (if I do not misunderstand it) and a PCIe. 

--- Quote End ---  

 

 

JESD204 defines a protocol for transmitting the ADC data using high-speed transceivers. 

 

http://www.eetimes.com/design/analog-design/4371745/an-overview-of-the-jesd204-standard-for-analog-d... 

 

It is up to you to figure out how to get the data from the ADC to the Cyclone IV GX board. 

 

If you were going to design your own board, then you could plug the Cyclone IV GX PCIe connector into your board. However, if you were going to go to that much trouble, you may as well put the FPGA on the board too. 

 

At this point you haven't really described enough detail to provide help. 

 

Cheers, 

Dave
Altera_Forum
Honored Contributor I
68 Views

The ADC outputs 8-bit or 10-bit. I have not figure out how to transmit data to FPGA, perhaps in series, since my board seems can only receive the data in series. But now by your response, I find it is too difficult to handle the interface problem. I wonder except for Cyclone IV development board, what other boards (may not altera) would you recommend me to do such work. I found the price of board that has build-in ADC is above 1000 dollars. I cannot afford much for I'm still a undergraduate student and the fund provided by my supervisor is around 500 dollars. 

I also found Cyclone III starter kit seems can interface with a daughter board but for the same reason, it costs much. It is my last choice I think. 

But I found Cyclone III starter kit has a HSMC connector. If I have this HSMC connector, what should I do next? Choose ADC has HSMC connector also? 

I'm grateful for your help.
Altera_Forum
Honored Contributor I
68 Views

Lets start from scratch and see what you really need. 

 

What is the signal you are sampling? Why do you need 8-bits or 10-bits? 

 

If we can understand the problem you have been given, perhaps we can find a solution that will work with the hardware you have. 

 

Cheers, 

Dave
Altera_Forum
Honored Contributor I
68 Views

Okay, my project is to use 10MHz electronic signals as my information carrier.  

1. I define that if I receive a 10MHz signal during a time period, then it is logic 1. If not, it is logic zero.  

2. At the sending end, these logic 1s and 0s are sent by another board to drive a transducer to output the 10MHz electronic signal, through a complex channel, become a FM signal and finally it will be demodulated to a roughly 10MHz signal by FM demodulator.  

3. At the receiver end, my idea is to use ADC to detect this roughly demodulated 10MHz electronic signal to digital data, for later FFT analysis. And I think 8-bit perhaps is enough (I'm not sure) for analysis because I have only to detect a single tone signal and it saves much space for storing. The receiver I choose is this FPGA (it is given by my supervisor actually) because it is fast. Later on this FPGA put all collected data to my computer and I do the analysis.  

4. After the analysis, the last step is to compare the original digital data to my decoded data (10MHz is logic 1, no signal is 0)and gives the error bit rate. 

 

(I have another PFGA "spartan 3a Starter Kit" that has a build-in ADC but its sampling rate is only 1.5MHz. I'm trying to know whether it can work with an external ADC, the same question I ask here to find ADC to work with Cyclone IV) 

 

You told me to use JESD204, and I found this demo board, ADC1413D065W1. It seems it can meet my requirement. What do you think? 

 

Many thanks for your time
Altera_Forum
Honored Contributor I
68 Views

 

--- Quote Start ---  

 

What do you think? 

 

--- Quote End ---  

 

 

You do not need any hardware at this point. You first need to design your system, and simulate it. 

 

 

--- Quote Start ---  

 

Okay, my project is to use 10MHz electronic signals as my information carrier.  

1. I define that if I receive a 10MHz signal during a time period, then it is logic 1. If not, it is logic zero.  

 

--- Quote End ---  

 

 

If your signal is at 10MHz, then there are multiple ways of detecting whether it is there or not. If you were going to sample the signal so that it is within the first Nyquist zone of an ADC, then you actually need an ADC with better than 20MHz sampling frequency. How much better depends on your analog filter. 

 

Depending on the spectral content of your signal, you can sample at a slower ADC clock rate, and alias the signal. This requires that the analog input bandwidth of your ADC include 10MHz. You could read the data sheet for the ADC on your Spartan board and see what its analog input bandwidth is. 

 

You could also consider using the Cyclone IV GX receiver as a 1-bit ADC sampling at 3GHz clock rate. You can then digitally filter the signal to improve the signal-to-noise (number of bits) in the result. 

 

The key point here is that you need to design your system. The design stages involve 

 

1) What hardware do I have access to? 

 

2) Play with ideas in software, eg., MATLAB 

 

3) Select the idea 

 

4) Simulate in Modelsim 

 

5) Synthesize and test in hardware 

 

6) Iterate 

 

Cheers, 

Dave
Altera_Forum
Honored Contributor I
68 Views

Wow, to use Cyclone IV as a 1-bit ADC sounds very cool. What should I care about using this method? The voltage level connected to SMA connector, LVDS or something else? 

Your advice is right. I should involve some simulation before the hardware stage.  

Thanks very much~
Altera_Forum
Honored Contributor I
68 Views

 

--- Quote Start ---  

Wow, to use Cyclone IV as a 1-bit ADC sounds very cool. What should I care about using this method? The voltage level connected to SMA connector, LVDS or something else? 

Your advice is right. I should involve some simulation before the hardware stage.  

 

--- Quote End ---  

 

 

So long as you do not violate the input voltage range of the transceiver, its no problem. You can also use an external 1-bit comparator. Hittite, InPhi, and others have parts. To synchronously sample at 1-bit, you need to force the transceiver to stay in lock-to-reference mode. You can also use a couple of comparators and create a 2-bit/3-level ADC. 

 

The downside of the 1-bit ADC is that you lose amplitude/power information, since you are essentially detecting just the zero crossings. However, you can recover that with an external power measurement. 

 

A 1-bit ADC is not necessarily appropriate for your application - so don't set your heart on it just yet - the key is to design your system before diving into hardware. 

 

Cheers, 

Dave
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