distribution problem?

Discussion in 'General Electronics Chat' started by Gibson486, Jan 6, 2015.

  1. Gibson486

    Thread Starter Member

    Jul 20, 2012
    I am trying to make this board that will enable to to program multiple similar chips with just a push of a button. To do this, I just hook up my MKII programmer and fanout the signals and control which IC gets the clock with a multiplexer. It worked when I did it with 2 Arduinos. However, I made the board and it seems to only program half the time (there are about 18 programmable chips on a board). The error is usually that there is a communication error. I am figuring that maybe when I go past 4, I start getting power consumption issues or maybe it is a signal integrity thing. Any thoughts?
  2. #12


    Nov 30, 2010
    Current limitations, speed, length of wiring, parasitic capacitance...
    High frequency stuff can get very picky.
  3. GopherT

    AAC Fanatic!

    Nov 23, 2012
    current draw and fan-out are the likely issues. As #12 said, the stray capacitance that makes nice digital signals look like weak sine waves can also be an issue with bigger boards.