DIP Circuit Alternative to PCA9547D SOIC Chip

Discussion in 'General Electronics Chat' started by mfad, Jul 23, 2014.

  1. mfad

    Thread Starter New Member

    Jul 23, 2014
    2
    0
    Hey,

    I was wondering if you guys could lend a helping hand on one of my problems or at least send me in the correct direction.

    I am trying to redesign a circuit and one of the components being used is:

    PCA9547D 8-channel I2C-bus multiplexer
    Datasheet: http://www.nxp.com/documents/data_sheet/PCA9547.pdf

    This chip is a SOIC and I would rather use a DIP multiplexer with the same functionality. It would allow for accessibility and easy integration.

    Is this feasible? Are there alternatives? How do I go about this problem? Any help you could offer would be great! Thanks!
     
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Sorry I don't have any suggestions a to alternates, though if I did it would just be a temporary solution.

    Check the time: it's 2014. DIPs are so 1980's. Manufacturers are coming out hourly with novel useful new devices, and they target today's market: surface mounted devices.

    Things just ain't available for thru hole mounting anymore. You can either run and hide or join the trend.

    Hand me a resistor with leads today and I just look and blink at it while thinking "how do I mount this?" That's because I made the jump to SMD a few years ago and think it is far superior, not only for production PCB work but for breadboarding too.

    So what to do with an SOIC? Use an adapter board to finagle it back into a DIP pattern. I keep many many sizes in my box so they are available right the bleep now when I want to use one. Plus free shipping isn't fast, but the parts are cheap if you search them out on places like EBay.
     
  3. mfad

    Thread Starter New Member

    Jul 23, 2014
    2
    0
    Thanks for all the help. This has really helped me understand what is going on with the circuit.

    Alright so after additional research today I have a different path that I would like to take. Hope you can help!

    Apparently a lot of the features are current not being used in the PCA9547D and thus I have reduced it down to a simpler circuit.

    PCA9540B 2-channel I2C-bus multiplexer
    PCA9540D.pdf

    Currently two HMC5883 sensors are hooked up to an Arduino I2C bus, but have fixed addresses and thus require a multiplexer.

    Here is my new idea:

    Both sensors have the same clock rate and was wondering could those clock lines be combined because they both share the same frequency and are being read at separate times?

    If so this would simplify the multiplexer into something along the lines of using a few digital logic gates (DIP Package)to switch between the address lines of the two sensors. I can see a few problems which I am looking into... the logic gates would have to wait for a LOW or HIGH signal from the Arduino and would need to switch at a high speed. They would also need to be bi-directional logic gates (If those exist).
     
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