Make before break (MBB) analogue switch, almost non existent

Discussion in 'General Electronics Chat' started by f_mohsen, Apr 7, 2016.

  1. f_mohsen

    Thread Starter New Member

    Apr 7, 2016
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    I require a make before break analogue switch for a project I am working on. The problem as I have been finding out is that the majority of the analogue switches are Break before make (BBM). For example Analog produces the ADG619 and ADG620 switches. The ADG619 (BBM version) can be easily bought from places like Farnell, but the MBB version ADG620 is no where to be found. The switch I need is a SPDT which can handle both positive and negative signals, as well as being MBB. Has anyone came across this problem? any component suggestions?
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Try using two SPST switches instead and control the make/break sequence and overlap time yourself (with timer circuits, or microcontroller, etc)
     
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  3. Kermit2

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  4. f_mohsen

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    Apr 7, 2016
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    Thanks for your quick response, it sounds like a good solution which I might end up having to do if I can't find the right hardware. But it seems very strange that this switch type is not readily available (I understand that it is less popular for many reasons, least of them shorting the inputs together).
     
  5. f_mohsen

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  6. KeepItSimpleStupid

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    Mar 4, 2014
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    ADG620

    $100 min. /line item

    https://www.rocelec.com/

    Rochester, I believe, is allowed to make products that are obsoleted by the manufacturer buts still has a demand and they are sanctioned by the manufacturer.

    You can also check www.littlediode.com

    http://www.littlediode.com/components/search.php?mode=search&simple_search=Y&posted_data[by_title]=Y&posted_data[by_shortdescr]=Y&posted_data[by_fulldescr]=Y&posted_data[by_sku]=Y&posted_data[including]=all&substring=ADG620BRM&search_redirect=Y for

    They are a really nice company to deal with and usually respond promptly.

    If this is for audio/video you might find better solutions.
     
    Last edited: Apr 7, 2016
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  7. f_mohsen

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    Apr 7, 2016
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    This is very interesting, I did not know about that website, but kinda expensive (gotta look at it in more details). What better solution do you have in mind for Audio?
     
  8. KeepItSimpleStupid

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  9. dannyf

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    Sep 13, 2015
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    It is possible to construct such a switch?

    :)
     
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  10. Marcus2012

    Member

    Feb 22, 2015
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    Hey :)
    There is the 4016 and 4066 of the 4000 series that are bilateral switches but I'm not sure if they are MBB.

    Not sure if this fits the bill or is the right package but is this the type of switch you're after?


    TS5A3154 0.9-Ω SPDT ANALOG SWITCH

    MBB time of 12ns and only one channel though
     
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  11. crutschow

    Expert

    Mar 14, 2008
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    Why do you need MBB?
    What is the application?
     
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  12. f_mohsen

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    Apr 7, 2016
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  13. f_mohsen

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    Apr 7, 2016
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    TS5A31454 would be perfect but the problem is that it only operates with positive supply, I need to pass both positive and negative signals.
     
  14. f_mohsen

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    Apr 7, 2016
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    I am using it in a way that it is not suppose to be used, at the output I have a capacitor. The sudden change in the capacitance of the switch causes a big charge transfer and high voltages for the next stage, thus causing it to rail for a short period of time. I am hoping MBB would at least reduce the degree of this sudden change in capacitance.
     
  15. GopherT

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    Nov 23, 2012
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    Or you could limit your switching to only when the signal is at the DC bias voltage so the charge on capacitors is always at the bias voltage.
     
  16. f_mohsen

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    Apr 7, 2016
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    Hhmm, maybe, but I need to sample the signal (and for that switch it) at specific time intervals, so I gotta play around with this idea, thanks
     
  17. GopherT

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    An ADC on a microcontroller should be able to handle your concerns at audio frequencies.
     
  18. crutschow

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    I don't quite understand.
    Could you post a diagram of what you are doing?
    There may be another way around your problem.
     
  19. f_mohsen

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    Apr 7, 2016
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    Please find attached, sorry if it is a bit rough, I do know that perhaps it is not the right way to use these switches.
     
  20. f_mohsen

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    Apr 7, 2016
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    Littlediode gave me the following quote:

    Quantity: 1-9 Pieces 10-19 Pieces 20-49 Pieces 50-99 Pieces 100+ Pieces
    * Price: £11.99 £11.69 £11.39 £11.09 £10.79

    seams reasonable for low counts of these chips, Thanks for the suggestion
     
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