New Project: Analog Acquisition board [UPDATE_1]

[Citizen]

Hello ppl! Hello Dave!
 I was following eevblog on youtube for a long time, and Dave gave me the final motivation to start to convert my knowledge in practical experience:).

 I have started with Arduino, but then realized it is a  toy, and i would be  better to  learn something more useful for  my future industry career:)
Then i have tried  Atmel µC's, but found the programming language (C)  and all those register shifting  a bit boring. Moreover µC are just too slow for my ambitions:D
 I switched to FPGA (Altera), and fell in love with its idea and VHDL:) Its damn fast, multifunctional,  has lots of IO, and VHDL is just  more intuitive.


Ok, now to the point.
My first (real) project is to  interface the CCD-Camera with my DE1 Altera Board, and then show the image on Display (VGA).After that is done , i will work on patter recognition... but that comes later=)
My CCD Module is this sexy beauty here:
http://www.motionanalysisinc.com/specs/jai/cvm77.pdf  (scored for 50 Euros on Ebay)
 It has lots of configuration that can be performed from my FPGA Board.

But first i have to  convert the analog video signal data to digital data. I decided to  start a sub-project, named "analog acquisition Board"

This board will contain 3 ADC : ADC08200  with 200 MSPS Max. (TI)
The reference voltage for the ADC will be generated by separate DAC's: DAC5311 (TI)
The heart of this board  will be Altera MAXII CPLD(570 LE) : EPM570T144C5N

The CPLD will control the ADC's and DAC's , preprocess the output  signal and other  misc. thing. Moreover  this CPLD unit will make this board  to  a stand alone module, that can be useed without additional FPGA Board. The Acquisition Board will be controlled via  SPI-Like interface.
So my goal is now to design a  versatile acquisition board, witch could be  later used with any kind of  Dev boards(even with Arduino!).
Moreover i have tried to keep the power consumption  low.You can command the CPLD to switch off  any unused ADC's or just to  lower the sample rate. (1 MSPS=1mW)
The board will also contain switchable Clock generator:LTC6905-133  (133Mhz ,66.7 Mhz or 33.3Mhz) (LT)
The  Voltage Regulator  REG104FA-3.3 (TI) handles 12V (or lower) input voltage and  provides 3.3 V for  the whole module. It can handle 1 Amp.
Currently my board is on its final stage:
I attach the unrouted PCB

I decided to place all passive  components(caps and resistors)  and  the DAC's on the bottom layer.
 The Top layer contain just "high speed"  things + some LEDS (D) for status indication  and debugging.To make this Board  even more multifunctional i will add 22 GPIO's and 2 communication ports for external controll of the CPLD

Since i am a complete noob in pcb designing(this will be first PCB in my life), i am asking here for some good tips and hints  about my component selection, placement and the whole idea as such:)
Is it a good idea to let Altium aoutoroute the whole board, or is it better to  do it manually?

Moreover i am curios if someone else is interested in this  small project, so maybe i will make this board available  as open source?=)

PS

I am thinking about  making a few tutorial videos about my main FPGA project(inkl. Sub Project): From  choosing components to first PCB Design and finally about  programming the FPGA/CPLD and showing the image an my monitor as  a result of many  hours of creativity:)) . Just not sure if there is enough ppl. interested in this stuff. 

TNX for reading
 

[jmole]

There are ADCs specifically for 3-channel video capture that may be a much cheaper solution than 3 discrete 200 MSPS ADCs.

Here's just one of many examples, the TVP70025I: http://www.mouser.com/ds/2/405/sles232b-127512.pdf

Very ambitious project! Good luck!

[saigai]

I'm also using TVP7002 on a similar project. It's pretty awesome for a newbie like me - 3x ADC, clock generation and other black magic all done for me.

[Citizen]

Yeah, i know there is special IC for video processing.
But then this board will be useful only for video processing, while my board  can be used   in many different application+ it has some processing power provided by CPLD;)
 By taking a simple IC i wouldn't learn how to design  own project

[saigai]

Yeah, i know there is special IC for video processing.
But then this board will be useful only for video processing, while my board  can be used   in many different application+ it has some processing power provided by CPLD;)
 By taking a simple IC i wouldn't learn how to design  own project

Good enough reasons to go the hard way! All aspects of your project are very interesting to me, and I do hope to hear more about it

[kt315]

When it come to pattern recognition, hardware solution is not exactly the first thing that comes to my mind. It is actually a huge work on it is own. There is an OpenCV project, which is currently de facto is a standard for such application.

You are seriously limiting what you can do with the image later on if you start with CPLD. Just a word of caution ...

I'd probably would be looking at linux boards if I wanted to do any kind of interesting image processing. But all depends on how much you want to do with it of cause.

[Citizen]

No no, you get me wrong:)
The MAIN processing will be handled on my Altera DE1 FPGA board.

The acquisition board just  serve as  fast AC-DC converter + preprocessing in the man project

[Citizen]

No  further suggestions?

[jahonen]

How are you going to generate the line locked clock for AD-conversion of the incoming video to prevent video jittering? To perfectly match your camera resolution, you'll want a line-locked 25 MHz clock for ADC. What about the black level clamping and synchronization separator?

Regards,
Janne

[Citizen]

My JAI CV-M77 has  PixelCLK output so i can sync. ADC with Pixeldata.
Moreover it has HD/VD input/output.
ith it i can  see when to start recording data, or i can trigger  it by myself:)

[jmole]

No  further suggestions?

My only comment is that you're embarking on a very ambitious project for your first PCB design. It sounds like you have a lot of experience otherwise, so you may be alright in this regard.

I would read as much as possible about high-speed PCB layout techniques. There are tons of application notes around that will help you in this endeavor. The more you know before you start, the fewer mistakes you'll make. That said, experience is by far the best teacher.

Second, I would highly recommend adding test points *everywhere*, inasmuch as you can get away with it. It can be very frustrating to debug a complex design when you can't fit your probes into the places they need to go. You'll also want to ensure that the test points dont add any reflections or impedance mismatches to your signal, data, and clock lines. One easy way is just to add an untented via of sufficient size to the traces you care about. Later, if you need to probe, you can either solder a testpoint to the via, or probe it directly with your oscilloscope.

Good luck!

[Citizen]

Hi.
Tnx for advice.
I really orgot abouzt test points at all.
Furthermore have decided to read  literature about high speed PCB, before routing  the PCb manually.
This way i will learn even more:)

P.S
Is 150 Mhz  really high speed league?

[jahonen]

P.S
Is 150 Mhz  really high speed league?

Like it has been said many times on this forum, it is not the clock frequency but the edge rate of your signals. You might experience high speed signal issues regardless of the clock rate if your edge time starts to be comparable to the propagation delay of your PCB traces. Traces with uncontrollably high impedance are usually the worst offenders.

Regards,
Janne

[Citizen]

Hello There:)
The project go on. I finally managed to  design a PCB. It is  almost finished.

But because it is my first serious project and  first PCB, i would like to have a feedback from experienced users here. I will attach the gerber  files. Please take a look, if you don't mind:)

I took 250 Mhz XO as Main Clock, and will use  a devider in CPLD, to  drive ADC.
Instead of using VGA connector i will  use a convenient BNC for each channel:)

[Harvs]

Mate, if you want people to seriously look at your board, you need to do more than give them the gerber files.

From the renders, looks like you're using altium.

Just use the Smart PDF function, do it on the whole project (so it includes both schematic and PCB layers), then right click in the layer set area and create final which will include a page for each of the layer sets.

Then you've got a PDF from which people can have a reasonable chance of giving feedback. 

[Citizen]

Thanks for advice. I am new to altium. Here  is the PDF File.

Some people are saying that my PCB   could be much smaller.Moreover   they say i  i have to switch to the 4-Layer PCB, with proper GND and PWR plane.  That will keep size down, so the price should be about the same.
Any suggestions  ?