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crosspoint switch

I want to feed 12 channels of RGB signals, 1 Y/C signal (i.e.) 38 signals as input to crosspoint switch. The available crosspoint switch (ADV3201) supports only 32 inputs : 32 outputs. I want to derive 2 outputs from any input channels that I want without any limitation. So kindly suggest me Analog devices parts to implement my logic.

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  • FormerMember
    FormerMember
Aug 16, 2018 +1

A1) Yes you can run all the same colors through one device

A2) Only the 3 channel parts are avaliable.

B) same answers as in part A

C) 1-13 analog buffer?  Other than a large array of op-amps with good…

on Aug 13, 2018 2:14 PM

Hello,

The ADV7625 is not what you are looking for.  I am looking at the issue now and will have a recommendation shortly as I review the available solutions

  • Let me restate the problem a bit:

    1) input 12 x RGB analog channels

    2) input 1 x Y/C analog channels - treat this as 1 RGB analog channel

    3) Total of 13 RGB analog input channels to deal with, or 3x13 = 39 input signal paths

    I assume you only need 13 outputs and when you say 2 outputs of any one input channel, this will cause blocking of another input channel

    4) output 13 x RGB analog channels, total of 39 output signal paths

    As you've noticed the ADV3201 is only 32x32.  So you will need to use two ADV3201s where the first parts only muxes the R & G portions of the input and the second part muxes the B portion of the input channels

    5) Part 1 would mux R & G or 2x13 (26) signal traces and Part 2 would mux the B or 1 x 13 (13) signal traces.

    Three ADV3201s can handle 32x32 RGB muxing 

    This is the same approach I used to design a 32x32 HDMI matrix switch only using four 64x64 digital cross points devices.  I split the channels up into 4 parts and ran each part set through individual devices.

  • Hi,

       You have understood the problem that i have stated and I am glad that you have given me a good solution but 3 ADV3201 is costly to afford. Can you provide me a solution to implement the same giving me provision to choose any inputs as my output with any Analog devices parts or combination of 2 crosspoint switches with different part numbers fulfilling my requirement? I want only 2 outputs and in that case blocking of remaining input channel is not a problem for me.

  • You have to look at this problem as needing three 13x13 matrix switches.  This can be accomplished with:

    1) three 16x16 parts (ADV3227)(cost ~$150) where each part handles one of the three 13x13 matrix switch sets  (wastes 9 input-output paths)

    2) two 32x32 parts (ADV3201)(cost ~$200) where the first part handles two 13x13 matrix switch sets and the second part handles the third 13x13 matrix switch set. (wastes 25 input-output paths)

    3) One 32x32 part (ADV3201)(cost ~$100) and one 16x16 part (ADV3227)(cost ~$50).  The 32x32 would handle two 13x13 matrix switch set while the 16x16 part would handle the third matrix switch set.  (wastes 9 input-output paths)(cost ~$150 total)

    4) A Clos Network style using 8x8 parts (like AD8109) would require at least 5 parts on both input and output layers costing ~$200.  This does not include in internal layers.

    5) Custom designed matrix switch based on analog switches like the ADG1606 and lots of op-amps.  Here you would have to watch out for the bandwidth and total system cost including total part count and required PCB space to implement the 3x13x13 matrix switch.

    Note these cost are directly from the web site and maybe different depending on you supply chain.

    Also you have never mentioned the max RGB format.  We would need this to determine the required bandwidth of the parts.

    My pick would be option 3.  Fewest parts, lowest cost, lower power requirements.

  • Hi,

         Thanks for your valuable suggestions. I have come up with two ideas and I need your advise on implementing it. I want to know whether I could go ahead with the following methods or not.

    METHOD 1 :  Using one 32x16, one 16x8 crosspoint switch.

    NOTE : Aim is to feed 13 channels RGB (STANAG3350B) inputs and derive 3 RGB (STANAG3350B) outputs. Can you confirm whether this approach is correct or not?

    For ADV3203:

    1. “NC” represents  “No connection”.
    2. 13 Red “R”, 13 Green “G” signals are fed to the ADV3203 which is 32 x 16 crosspoint switch.
    3. The outputs are as follows : 3 Red signals and 3 green signals are taken as outputs.

    For ADV3225:       

    1. “NC” represents  “No connection”.
    2. 13 Blue “B” signals are fed to the ADV3225 which is 16 x 8 crosspoint switch.
    3. The outputs are as follows : 3 Blue signals are taken as outputs.

    ---------------------------------------------------------------------------------------------------------------------------------------------------------------

    METHOD 2 : Using three 16x8 crosspoint switch.

    NOTE : Aim is to feed 13 channels RGB (STANAG3350B) inputs and derive 3 RGB (STANAG3350B) outputs. Can you confirm whether this approach is also correct or not?

    For ADV3225:

    1. “NC” represents  “No connection”.
    2. 13 Red “R” signals are fed to the 1st ADV3225 which outputs 3 Red signals.
    3. 13 Green “G” signals are fed to the 2nd ADV3225 which outputs 3 Green signals.
    4. 13 Blue “B” signals are fed to the 3rd ADV3225 which outputs 3 Blue signals.

    -------------------------------------------------------------------------------------------------------------------------------------------------------------

  • Ah, I misunderstood the topology you wanted.  I though it needed to be 13x13 RGB which lead me to the 32x32 parts.

    Both methods above will work for 13x3 RGB matrix switch.  I prefer method #2 since I like symmetry, both in parts and layout.  Cost would be about the same.

  • Thanks a lot for your support. Your suggestions did resolve my issues and provided me a feasible solution!

    I have few queries regarding :

    A) Triple Differential Receiver AD8145 

    B) Triple Differential Driver AD8146

    C)  1 differential signal to 13 differential signal

    A : Problem description of AD8145 :

    My aim is to convert the Differential RGB(STANAG3350B) signals to single ended RGB(STANAG3350B) signals. You know that I am grouping my Red signals, Green signals, Blue signals of all channels.  Consider that I have 3 Red signals , 3 green signals and 3 blue signals which I want to convert to single ended signal using this IC. Hence I have to use 3 such ICs.

    1. Can I connect all my 3 Red signals to the 1st IC, 3 blue signals to my 2nd IC, 3 green signals to my 3rd IC?

    2. This IC supports only 3 differential inputs. Can you suggest me an IC which supports more than 3 differential inputs for the same application?

    ---------------------------------------------------------------------------------------------------------------------------------------------------------------

    B : Problem description of AD8146 :  (This problem is the vice-versa of above problem description)

    My aim is to convert the single ended RGB(STANAG3350B) signals to differential signals ended RGB(STANAG3350B) signals. You know that I am grouping my Red signals, Green signals, Blue signals of all channels. Consider that I have 3 Red signals , 3 green signals and 3 blue signals which I want to convert to differential ended signal using this IC. Hence I have to use 3 such ICs.

    1. Can I connect all my 3 Red signals to the 1st IC, 3 blue signals to my 2nd IC, 3 green signals to my 3rd IC?

    2. This IC supports only 3 differential inputs. Can you suggest me an IC which supports more than 3 differential inputs for the same application?

    ---------------------------------------------------------------------------------------------------------------------------------------------------------------

    C : Problem description:

    My aim is to convert 1 Differential sync signal to 13 differential sync signals. Can you suggest me few parts to implement the same.

     

  • A1) Yes you can run all the same colors through one device

    A2) Only the 3 channel parts are avaliable.

    B) same answers as in part A

    C) 1-13 analog buffer?  Other than a large array of op-amps with good circuit design you might look at the ADV3201, 32x32.  Just use one input pair and map 13 output pairs to the same input.

    For parts A & B I'd run one RGB channel through the same chip, not split it across three chips.  Trace lengths for one channel need to be keep the same.  Mismatched trace lengths will cause phase differences between the color signals creating possible color ghosting.

  • Thanks! Your suggestions really helped me optimise my design.